Add support for CurrentPatchSet
Add support for CurrentPatchSet

The "currentPatchset" field of the query results includes information
about the review label scores.

Change-Id: I41d54225284e15b2b61b79bfaa309cd5c2b4b86a

dpursehouse/pygerrit2,dpursehouse/pygerrit,markon/pygerrit2,gferon/pygerrit2,sonyxperiadev/pygerrit,benjiii/pygerrit,morucci/pygerrit