added consistency level to BasePolicy
added commit level to WritePolicy
Use pooled XOR shift random number generator for TaskId generation
Added LargeList.Range and LargeList.RangeThenFilter methods
Added LargeList.Range and LargeList.RangeThenFilter methods
Added LargeMap.Exists method
Updated CHANGELOG.md
added go v1.4 build target to tests
run all tests on Travis
go tools location fix for TravisCI