Added FocusItem and FocusItemList.
DropIntoArray action and test.
Added FrameWidget.
Added FramesTimeline.
Added FramesTimelineTest.
Added description to Frame#time .
Added StretchableButton, you can change it size by dragging.
Comments addressed.
Adjusted EditorGameAssets#resolve and test fix.
Merge pull request #667 from gorco/StrButton

Added StretchableButton.
Merge pull request #663 from RotaruDan/FramesTimeline

Frames timeline