Disabled states, more UX work, bug fixes.

Fix drawable state to correctly show dimmed disabled state.  Update
disabled state for all children to grey out text.

Block multi-selection of documents not matching MIME filter.  Load
thumbnails in parallel.  Show thumbnails in list mode based on MIME
type to match spec.

Give each footer a unique view type to avoid recycler crashes.

Show breadcrumb icons in recent create paths.  Fix timestamp bug when
querying/updating recent paths.

Make ContentProviderClient.closeQuietly() really be quiet.

Bug: 10668364, 10510022, 10668701, 10534224, 10667726
Change-Id: I3c705412fb211519f15ad41a273a7533b878e9e5