* Moved Slate.h into SlateBasics.h and began shifting less commonly used headers into SlateExtras.h.
* Slate.h now simply includes SlateBasics.h and SlateExtras.h.
* Slate.h includes a deprecated warning now to indicate that SlateBasics.h + specific includes should be used instead.
* Moved dozens of inlined functions using Slate widgets into .cpp files to avoid header dependencies.
* All code samples now include SlateBasics.h and SlateExtras.h so future shifts will not break most those projects, but not trigger the deprecation warning of including Slate.h.
#BUN
[CL 2329610 by Wes Hunt in Main branch]
#branch UE4
#proj Editor.ComponentVisualizers, Editor.UnrealEd, Runtime.Core, Runtime.Engine
#change FInterpCurve now uses a binary search to obtain the correct key. Removed the optional out-parameter on Eval, EvalDerivative, etc. Removed FORCEINLINEs on large methods.
#change USplineComponent now builds the remap table with points spaced at equal distances, which leads to better results. Added internal methods to obtain the segment length, and the interpolation parameter along the segment at a given distance.
#add Added Duration to USplineComponent.
#add Added a number of different methods for obtaining position, tangent and rotation at a specified distance, or a specified time (optionally at constant velocity).
#add Added methods for building the spline procedurally.
#add Supports right-click context menu on ComponentVisualizers in the standard interface.
#add Key tangents can be manually edited.
#change FLevelEditorViewportClient::ProcessClick now handles right clicks to the Unreal gizmo in the same manner as left clicks, i.e. the method recurses using a version of the hit proxy with the gizmo removed, so we can look at what's underneath. This allows for "genuine" context menus, i.e. depending on what was clicked, instead of using a single default provided by the current level editor.
#reviewedby James.Golding
[CL 2089561 by Richard TalbotWatkin in Main branch]
