First pass at Materializing DocumentsUI!

Initial Material asset drop, which still needs some tweaking.  Moved
back to framework list item selectors, giving us ripples.  Using
accent color overlay for activated items.  Align all items to new
Material grid, including insetting list divider and resizing list
items on wide screens.

Fix obscure RTL drawing bug.

Still lots of work left.

Bug: 15836082
Change-Id: I729cc7dcb0271ee62b55d1e036fc28427fc0dd3d