EAGLESIX-2698: Just added a couple simple test cases.
Updated ObjectExpression and corresponding test cases to mongo 2.6.5.  Made a change in FieldPathExpression to make an analogous change for a failing unit test case (addDependencies()) before bailing out on the test cases for now because so many are failing.  This may be due to more needed changes in FieldPath or FieldPathExpression.
Changes to date and time expression classes
Remove debugger line from test case for ObjectExpression.js
Merge branch 'feature/mongo_2.6.5_expressions_ObjectExpression' of https://github.com/RiveraGroup/mungedb-aggregate into feature/mongo_2.6.5_expressions_ObjectExpression
Actually remove the debugger line
Add DateToStringExpression.js
EAGLESIX-2706 expression Compare ported to mongo 2.6.5
EAGLESIX-2708 expression Subtract ported to mongo 2.6.5
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-2712: minor changes and comments
EAGLESIX-2713: formatting
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
Merge branch 'feature/mongo_2.6.5_expressions' into feature/mongo_2.6.5_expressions_ObjectExpression
EAGLESIX-2697 Style edit to ObjectExpression
EAGLESIX-727 Expressions... DateToString.  evaluateInternal() change to return a null for null input