LIB_EXTRA: Fixed position on staggered grid
Cleanup
LIB: Added a ForegroundLayout
LIB: Added a ForegroundLayout
LIB: Added the method getCardThumbnailView in CardThumbnail
LIB-EXTRA: Fixed CardGridStaggeredArrayAdapter
DEMO-EXTRA: Added a BaseStaggeredGrid example
DEMO-EXTRA: Added a StaggeredGrid example
Merge remote-tracking branch 'origin/dev' into dev

Conflicts:
	demo/extras/src/main/res/values/strings.xml