Use a shorter version to build ImmutableSets
Check the incoming TSUIDS in Span
Use a constant for the empty annotation list in TestSpan
Cleanup TestSpan
Merge remote-tracking branch 'origin/next_query_test' into next_query_test
Allow Span to accept a mutable SortedSet but make a defensive copy instead
Merge branch 'next_query_test' of github.com:hi3g/opentsdb into next_query_test