New version of SampleSyncAdapter sample code that allows local editing

The changes made were
pretty sweeping. The biggest addition was to allow on-device contact
creation/editing, and supporting 2-way sync to the sample server that
runs in Google App Engine.

The client-side sample code also includes examples of how to support
the user of AuthTokens (instead of always sending username/password
to the server), how to change a contact's picture, and how to set
IM-style status messages for each contact.

I also greatly simplified the server code so that instead of mimicking
both an addressbook and an IM-style status update system for multiple
users, it really just simulates an addressbook for a single user. The
server code also includes a cron job that (once a week) blows away the
contact database, so that it's relatively self-cleaning.

Change-Id: I017f1d3f9320a02fe05a20f1613846963107145e
45 files changed