9c6e5376e6
Adding ability to specify a user or group by:
* Adding a ',' after the label name followed by a reviewer id
or 'user=' and the user id.
e.g., label:CodeReview=1,jsmith
label.CodeReview=1,user=jsmith
* Adding a ',' after the category name followed by a group id
or 'group=' and the group id.
e.g., label:CodeReview=1,android_bait
label:CodeReview=1,group=android_bait
The user specific label query is backed by the label field in Lucene.
The filtering on the group is done only after results have been
retrieved from Lucene and thus it is more expensive.
Change-Id: I39a1000712743a6ed238e70d45c0ccc1eec50031