Merge pull request #36 from tgf/evergreen

Native filter compound slicer and native existing minor fixes
[MONDRIAN-2086] fixed dialect issue with native sum sql generation
[MONDRIAN-487] flush schema cache to avoid cache corruption in downstream
tests.
[MONDRIAN-1861] added slicer tuples so that native eval can utilize full
context of the slicer.  Added optimize function to simplify the slicer
tuples to only those in context.
[MONDRIAN-1654] fix for sets and compound slicer, moved initial eval of
regular axis below the full evaluation of the slicer.
[CLEANUP] tidy up addContextConstraint a bit, accidental import
[MONDRIAN-1861] workaround: avoid native execution for disjoint compound slicer

had put a trivially wrong result in testSlicerTuplesPartialCrossJoin
temporarily using the placeholder as an all-purpose placeholder
[MONDRIAN-1861] nativize slicer tuples when disjoint or multilevel

main change: SqlConstraintUtils.addContextConstraintTuples
only using when detected disjoint or uneven levels
added slicer tuple to native constraint key
still using placeholder
some accidental indentation changes
[MONDRIAN-1861] use evaluator instead of placeholder (merge last commit)

also, using optimizedSlicerTuples now
[MONDRIAN-1861] minor clean in SqlConstraintUtils
[MONDRIAN-1861] enable multivalue in expressions for vertica

for more compact slicer tuple constraints
Merge pull request #37 from tgf/nativeTuplesSlicerMerge

Native tuples slicer merge
[MONDRIAN-1572] Support Many To Many Native Evaluation in Slicer for both
regular and Compound Slicer scenarios.  Also addressed a few other issues
in Native evaluation with tests cases added to NativeSetEvaluationTest.
[MONDRIAN-2049] compound slicer members were not factored in aggStar selection for Children

fixes NPE with agg enabled in
 NativeSetEvaluationTest.testConstraintCacheIncludesMultiPositionSlicer
 BasicQueryTest.testCompoundSlicerNonEmpty