Merge pull request #7 from derek63/master

Add a bunch of stuff for client and requests
Add ValueExpression class
Adding other constructor for ValueExpression
Making ValueExpression toString call toJson
Basic ValueExpression unit test
added to string for all enums
Adding test for ValueExpression checking that toString calls toJson
Merge pull request #8 from derek63/master

Add set methods to LightblueRequest interface
Additional work on logical expression, consuming new methods on enums to simplify jsonization.
Merge branch 'master' of github.com:lightblue-platform/secant
Updating ValueExpression and its unit test to adhere to no-spaces-in-json convention
added FieldExpression