rename mapBlock -> mapFunction and ditto for reduce.
fix compile error
stub out CBLQueryRow()
started to stub out CBLQueryRow
ported methods in CBLQueryRow, working on Document. loadCurrentRevisionFrom() which one method depends on.
unit tests compile again
CBLCollateRevIDs() implementation
CBLCollateRevIDs() passes test
loadCurrentRevisionFrom()
CBLQueryRow all methods implemented