Add options to /changes/<id>/detail

Clients fetching the detailed information about a change need more
than just the labels, they also expect to see the current revision and
data from its commit.  Support the o/O options used by /changes/ to
permit clients to obtain more information than the default set.

Change-Id: Ic8f910474b8f13e6faf76199c5781a38075380ac
2 files changed