First revision of the new browser provider.

This one has support for bookmarks sync,
has the bookmarks and history in separate
tables, and supports hierarchical bookmarks.

Compatibility with the old APIs is not yet complete.

The Bookmarks UI has been switched over to the
new provider. Creating bookmarks puts them
in the UIs root folder.

Change-Id: Ib21713ddd19f43d178d49dbac977f749e7103368
17 files changed