Clarify LabelInfo documentation

Clearly split up the fields set by LABELS vs. DETAILED_LABELS, and
provide a one-sentence summary of each option. Provide more precise
definitions for approved/rejected/recommended/disliked, and indicate
that they only list one user per label. (Precisely which user is hard
to define, since it comes out of the submit rule evaluator.)

Change-Id: Ia3d5f5806766abdc15d6711ba6a6adcc30040ace
1 file changed