+ Add a toolbar button for adding additional objects to animate.
+ Add combo buttons to object binding tracks for adding additional property tracks.
+ Make the animation outliner resizable.
+ Add widgets for editing key values to the animation outliner.
+ Add buttons for navigating to previous and next keys, and for adding a key at the current time to the animation outliner.
[CL 2583673 by Frank Fella in Main branch]
+ Add the FSequencerSelection class and move all selection functionality there.
+ Add the concept of an active selection which is used to determine what to delete when the user hits the delete key.
[CL 2524575 by Frank Fella in Main branch]
+ For slots display the name of the widget in the slot and the panels name instead of the slot name.
+ Update the display name for the binding when the object's name changes.
[CL 2507310 by Frank Fella in Main branch]
#proj core
#branch UE4
#summary Rename Trunc, Round, Floor, Ceil to TruncToInt, RoundToInt, FloorToInt, CeilToInt. Added *ToFloat versions. Repeated for FGenericPlatformMath and all derived classes for all platforms wherever applicable. Corrected comment in Fractional and added Frac() which does HLSL-style fractional (x - floor(x)). Checked for compilation on all projects (with cooking levels wherever applicable). Didn't change Fractional to Frac, this will be done in second commit.
#codereview robert.manuszewski
[CL 2064306 by Mikolaj Sieluzycki in Main branch]
