EAGLESIX-2687 updated port of Value
Added unit test module with test cases for Document
Added instanceof assertions to clone unit tests
Remove unnecessary new Object calls
EAGLESIX-2651: initial port of Accumulator from v2.6.5
EAGLESIX-2651: initial port of FirstAccumulator from v2.6.5
EAGLESIX-2651: initial port of LastAccumulator from v2.6.5
EAGLESIX-2651: initial port of SumAccumulator from v2.6.5
EAGLESIX-2651: initial port of MinMaxAccumulator from v2.6.5
Merge branch 'feature/mongo_2.6.5_accumulators' into feature/mongo_2.6.5_accumulators_Accumulator

Conflicts:
	lib/pipeline/accumulators/Accumulator.js
Merge branch 'feature/mongo_2.6.5_accumulators' into feature/mongo_2.6.5_accumulators_First

Conflicts:
	lib/pipeline/accumulators/FirstAccumulator.js
EAGLESIX-2688 Minor changes. Added error codes to some Errors. Commented out a duplicate method.
Merge branch 'feature/mongo_2.6.5_accumulators' into feature/mongo_2.6.5_accumulators_Last

Conflicts:
	lib/pipeline/accumulators/LastAccumulator.js
Merge branch 'feature/mongo_2.6.5_accumulators' into feature/mongo_2.6.5_accumulators_MinMax

Conflicts:
	lib/pipeline/accumulators/MinMaxAccumulator.js
Merge branch 'feature/mongo_2.6.5_accumulators' into feature/mongo_2.6.5_accumulators_Sum

Conflicts:
	lib/pipeline/accumulators/SumAccumulator.js
EAGLESIX-2651: initial port of PushAccumulator from v2.6.5
EAGLESIX-2651: make create method in Push Accumulator static
EAGLESIX-2691 First stab at the templates VariadicExpressionT class.  It depends upon other classes that are not yet converted so it is not working.
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Document
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Variadic