Upgraded Json.NET from v5.0.6 to v5.0.8
Upgraded NUnit from v2.6.2 to v2.6.3
Fixed the "level" enum in the schema to be a set of lowercase strings and not integers
Added a custom ErrorLevelConverter

The ErrorLevelConverter converts the ErrorLevel enum to a lowercase string
Refactored the test project

- Moved schema related stuff into a SchemaTests and SchemaHelper class
- Moved the exception generation stuff into a TestHelper class
- Fixed the schema test to be based on a constant string
- Renamed test methods to be more descriptive
No spaces after sizeof() and typeof()
Added SchemaHelper.GenerateSchema with helper methods to adjust JSON.NET's schema generation

The bulk of the schema adjustment code is taken from https://json.codeplex.com/discussions/245604
Made all public fields in ExceptionFrame and StackTrace into properties

Public fields should be properties according to Microsoft coding guidelines and makes them easier to do reflection on in a uniform way in the new schema adjustment code in SchemaHelper.
Generated a new JSON Schema with the schema adjustment code in place