Remove Project.Id and use only Project.NameKey

We remove the secondary unique column Project.Id and change the
schema to rely upon only the Project.NameKey property.  This is
necessary to support databases which cannot do multiple unique
attributes on the same entity.

Change-Id: I1a9184d69e4779f8e9f755a151ce55c9b9efc4d6
Signed-off-by: Shawn O. Pearce <sop@google.com>
12 files changed