Changing permission denied error to 403

I'm changing the "Insufficient permissions" error to 403 because 401 is intended for users who are not authenticated. The 403, on the other hand, is intended for users who are authorized, but are not permitted access to the resource.

http://stackoverflow.com/questions/3297048/403-forbidden-vs-401-unauthorized-http-responses
Merge pull request #63 from FreakTheMighty/bugfix-status-code

Changing permission denied error to 403