Copying //UE4/Dev-Sequencer to //UE4/Main

==========================
MAJOR FEATURES + CHANGES
==========================

Change 2875025 on 2016/02/20 by Andrew.Rodham

	Sequencer: Cinematic viewport improvements
	  - Added optional letterbox overlay (defaults to 2.35:1)
	  - Added ability to change safe frame colors
	  - Added selected tracks' keys to the transport range
	  - Added buttons for jumping between selected tracks' keyframes on the transport controls
	  - Removed black padding around the viewport where possible
	  - Added ability to specify whether a combo button/menu anchor should close when its parent receives focus
	  - Separated logic of FGroupedKeyArea into FSequencerKeyCollection, so it can be used independently
	  - Added playback range to the viewport frame numbers
	  - All frame numbers are now spin boxes

	#jira UE-26429

Change 2875026 on 2016/02/20 by Thomas.Sarkanen

	Added console commands for recording sequences

	Changed plugin to a developer plugin so we can load it when the editor is in -game mode.
	Added Exec commands.
	Added some more logging to help diagnose problems when using commands.
	Added loading/saving of config for recorder settings (stored in Editor.ini).
	Also disabled controls in recorder window when recording.
	Added auto-saving of assets when in non-editor modes.
	Moved animation settings from UnrealEd to Engine module.

Change 2875036 on 2016/02/20 by Max.Chen

	Sequencer: Call RedrawAllViewports instead of RedrawLevelEditingViewports. In particular, this fixes some update issues when editing values in the key editors.

	#jira UE-26960

Change 2875046 on 2016/02/20 by Max.Preussner

	Sequencer: Fix so that clicking on UMG Animations doesn't dirty the scene.

	#jira UE-26249

Change 2875047 on 2016/02/20 by Max.Chen

	Sequencer: Add option to toggle display of channel colors/lines. View->Channel Colors

Change 2877138 on 2016/02/23 by Max.Chen

	Sequencer: Select corresponding track node when selecting key or section. Removed active/inactive selection since it was only being used in deletion and the rules for deletion are now dependent upon what is selected - delete keys and sections before deleting outliner nodes.

Change 2877143 on 2016/02/23 by Thomas.Sarkanen

	Added new math function: WindRelativeAnglesDegrees

	Given two angles in degrees, 'wind' the angle in Angle1 so that it avoids >180 degree flips.
	Good for winding rotations previously expressed as quaternions into a euler-angle representation.

Change 2877147 on 2016/02/23 by Thomas.Sarkanen

	Added the ability to import sequencer transforms from the root node of an animation sequence

	Intended for use after re-importing animations from DCC tools.
	Available in the right-click menu for transform tracks.
	Also added FindTrackBinding to UMovieScene so track bindings can be recovered from tracks.

Change 2877163 on 2016/02/23 by Max.Chen

	Sequencer: Add option to create keyframe sections as infinite. Sequencer defaults to true, UMG defaults to false.

Change 2877165 on 2016/02/23 by Max.Preussner

	Sequencer: Drawing vertical position lines when dragging keys

Change 2878748 on 2016/02/23 by Max.Chen

	Curve Editor: Switch curve type to user when flatting or straightening tangents.

	#jira UE-27277

Change 2878799 on 2016/02/23 by Frank.Fella

	Sequencer - Add folders support to the outliner.

Change 2880769 on 2016/02/24 by Andrew.Rodham

	Sequencer: Added ability to override runtime spawnable ownership in sequencer
	  - This is exposed as an option on spawnables "Keep Alive Outside Playback Range (In Sequencer)"
	  - Enabling this will stop spawnables from being destroyed when scrubbing outside of the playback range

	#jira UE-27205

Change 2880770 on 2016/02/24 by Thomas.Sarkanen

	Sequencer: Added countdown and recording indicator display when recording

	Also fixed extra popups added post-PIE when animation recordings auto shutdown.

Change 2880782 on 2016/02/24 by Max.Chen

	Sequencer: Snapping now also uses the current time as a possible snap time.

	#jira UE-26306

Change 2880793 on 2016/02/24 by Max.Chen

	Sequencer: Add +Animation to Animation track so that it's consistent with all other tracks that have a + button.

Change 2880812 on 2016/02/24 by Max.Chen

	Sequencer: Fix adjusting the leading edge of a shot section so that it cuts into the shot rather than adjusts the start time.

	#jira UE-26306

Change 2881624 on 2016/02/25 by Andrew.Rodham

	Changing shader version GUID to fix corrupt shaders in ddc

Change 2882408 on 2016/02/25 by Thomas.Sarkanen

	Asset/actors stored in TLazyObjectPtrs can now reference game content from engine

	This is a legitimate use case as lazy object ptrs are designed to reference assets/actors cross-domain.

Change 2882409 on 2016/02/25 by Thomas.Sarkanen

[CL 2899785 by Max Chen in Main branch]

Engine/Source/Editor/LevelEditor/Public/LevelViewportLayout.h

@@ -9,7 +9,31 @@
 #include "LevelEditor.h"
 #include "LevelViewportActions.h"
 
+class ILevelEditor;
 class SLevelViewport;
+class FLevelViewportLayout;
+
+/** Arguments for constructing a viewport */
+struct FViewportConstructionArgs
+{
+	FViewportConstructionArgs()
+		: ViewportType(LVT_Perspective)
+		, bRealtime(false)
+	{}
+
+	/** The viewport's parent layout */
+	TSharedPtr<FLevelViewportLayout> ParentLayout;
+	/** The viewport's parent level editor */
+	TWeakPtr<ILevelEditor> ParentLevelEditor;
+	/** The viewport's desired type */
+	ELevelViewportType ViewportType;
+	/** Whether the viewport should default to realtime */
+	bool bRealtime;
+	/** A config key for loading/saving settings for the viewport */
+	FString ConfigKey;
+	/** Widget enabled attribute */
+	TAttribute<bool> IsEnabled;
+};
 
 /** Interface that defines an entity within a viewport layout */
 class IViewportLayoutEntity : public TSharedFromThis<IViewportLayoutEntity>
@@ -24,6 +48,9 @@ public:
 	/** Optionally return this entity as an SLevelViewport. Legacy function for interop with code that used to deal directly with SLevelViewports */
 	virtual TSharedPtr<SLevelViewport> AsLevelViewport() const { return nullptr; }
 
+	/** Get this viewport's level editor viewport client */
+	virtual FLevelEditorViewportClient& GetLevelViewportClient() const = 0;
+
 	/** Check if this entity has an active play in editor viewport */
 	virtual bool IsPlayInEditorViewportActive() const = 0;
 
@@ -38,26 +65,9 @@ public:
 
 	/** Called to save this item's settings in the specified config section */
 	virtual void SaveConfig(const FString& ConfigSection) = 0;
-};
 
-class LEVELEDITOR_API FLevelViewportLayoutEntity : public IViewportLayoutEntity
-{
-public:
-
-	FLevelViewportLayoutEntity(TSharedRef<SLevelViewport> InLevelViewport);
-	virtual TSharedRef<SWidget> AsWidget() const override;
-	virtual TSharedPtr<SLevelViewport> AsLevelViewport() const override;
-
-	bool IsPlayInEditorViewportActive() const;
-	void RegisterGameViewportIfPIE();
-	void SetKeyboardFocus();
-	void OnLayoutDestroyed();
-	void SaveConfig(const FString& ConfigSection);
-
-protected:
-
-	/** This entity's level viewport */
-	TSharedRef<SLevelViewport> LevelViewport;
+	/** Get the type of this viewport as a name */
+	virtual FName GetType() const = 0;
 };
 
 /**
@@ -85,7 +95,7 @@ public:
 	 * @param LayoutString			The layout string loaded from file to custom build the layout with
 	 * @param InParentLevelEditor	Optional level editor parent to use for new viewports
 	 */
-	TSharedRef<SWidget> BuildViewportLayout( TSharedPtr<SDockTab> InParentDockTab, TSharedPtr<class FLevelViewportTabContent> InParentTab, const FString& LayoutString, TWeakPtr<class SLevelEditor> InParentLevelEditor = NULL );
+	TSharedRef<SWidget> BuildViewportLayout( TSharedPtr<SDockTab> InParentDockTab, TSharedPtr<class FLevelViewportTabContent> InParentTab, const FString& LayoutString, TWeakPtr<ILevelEditor> InParentLevelEditor = NULL );
 
 	/**
 	 * Makes a request to maximize a specific viewport and hide the others in this layout
@@ -258,7 +268,7 @@ protected:
 	TWeakPtr< class FLevelViewportTabContent > ParentTabContent;
 
 	/** The optional parent level editor for this layout */
-	TWeakPtr< class SLevelEditor > ParentLevelEditor;
+	TWeakPtr< ILevelEditor > ParentLevelEditor;
 
 	/** The current maximized viewport if any */
 	FName MaximizedViewport;