port to ndb, step 1 of N
port to ndb, step 2 of N
port to ndb, step 3 of N
log handler: drop backward compatibility for Comment entities
port to ndb, step 4 of N
port to ndb, step 5 of N
port to ndb, step 6 of N
port to ndb, step 7 of N
port to ndb, step 8 of N. all tests pass!
only log stream connects/disconnects when there are some
port to ndb, step 9 of N. manual tests pass, pushing this one to prod.

also includes a G+ bug: override __getattr__ to populate GooglePlusPage.as_source instead of __init__.
remove leftover debugging log message