Refactored AddDefaultColumnValues to SetDefaultColumnValues
Updated tests for SetDefaultColumnValues
Added HttpVariablesExtensions Tests
Added DateTimeExtension Tests
Moved UrlUtilityTests to correct project folder
Fixed NormalizePageName to return a filtered name instead of string.empty
Added StringExtensions Tests
Added JsonUtility Tests
Merge pull request #151 from erwinvanhunen/TestAdditions

Additional Tests
Merge remote-tracking branch 'contributor/defaultcolumnvaluesfix' into dev