Changes to date and time expression classes
Add DateToStringExpression.js
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
Added DateToString.js and started the test cases module
Added a few DateToString test case skeletons
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
EAGLESIX-727 Expressions: Date-related expression comments, finish DateToString
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
EAGLESIX-727 Expressions... DateToString.  evaluateInternal() change to return a null for null input
EAGLESIX-727: Resolve conflicts in date classes
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
EAGLESIX-727: Get most test cases working for dates
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
EAGLESIX-727: Passing test cases for Date-related expressions
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date
EAGLESIX-727: Removed DateToString. From whence did it come? Verily I do not know.
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_Date

Conflicts:
	lib/pipeline/expressions/Expression.js
EAGLESIX-2651: Date/Time: tweaks for review of 2.6.5 port of date and time related expressions
Merge pull request #27 from RiveraGroup/feature/mongo_2.6.5_expressions_Date

Feature/mongo 2.6.5 expressions DayOfMonth, DayOfWeek, DayOfYear, Hour, Millisecond, Minute, Month, Second, Week, Year