A bunch of updates to BrowserProvider2.

The images are now shared between the history
and bookmarks tables so updates to one are
reflected in the other.

Added a parameter for specifying a limit when
calling query().

Added a combined view of history and bookmarks.

Added a way to get a distinct list of the
accounts providing bookmarks.

Added the ability to find the server unique
IDs for parent and insert_after when doing
a query for a row.

Change-Id: I9afa15bcf7ca68468793c49fbec701e516e4540e
7 files changed