Minor refactoring in tests
TODOs
Merge branch 'new_visibility' of https://github.com/apurtell/hbase-private into new_visibility
Move label exceptions into hbase-client
Improve the visibility labels attribute name
Add Mutation#setAuthorization
Merge remote-tracking branch 'private/new_visibility' into new_visibility

Conflicts:
	hbase-server/src/test/java/org/apache/hadoop/hbase/mapreduce/TestImportTSVWithVisibilityLabels.java