EAGLESIX-2706 expression Compare ported to mongo 2.6.5
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Compare

Conflicts:
	lib/pipeline/expressions/CompareExpression.js
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Compare
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Compare
EAGLESIX-2706 Ported mongo test cases
EAGLESIX-2651: Compare: missed test, reduce deviations w/ 2.6.5 code, simplified tests a bit, minor formatting
Merge pull request #24 from RiveraGroup/feature/mongo_2.6.5_expressions_Compare

EAGLESIX-2706 expression Compare ported to mongo 2.6.5