Rename reviewdb package to entities and dissolve client package

This is long overdue renaming step to manifest that SQL database is
removed from gerrit core. Moreover, client/server package division
was needed due to GWT UI that was removed as well in release 3.0.

Bug: Issue 11678
Change-Id: Icfd83a309a6affac54141e7284e70f1255537dc4
6 files changed
tree: 4e20a42eb8604e7386f91977fd06741ddf089291
  1. java/
  2. javatests/