Fix compiler warnings on Mono

Fix references for Mono

Fix Rakefile to compile on Mono

Copy NewtonSoft JSON into publish directory
Merge pull request #18 from webcoyote/compile-on-mono

Fix compiler warnings on Mono
Include 'error#context' as the context in the MVC test
Add code_version field for Rollbar resolutions

See https://rollbar.com/blog/post/2013/09/17/resolving-rollbar-items-in-versions