Parse errors that Fitbit returns to allow for more specific error handling in clients.
Fix get user profile to correctly use user id if passed in
Add tests for error parsing
Add retry after info to exception. Switch rate error check to use status code -- will start working on 5/27/14 per https://wiki.fitbit.com/display/API/Rate+Limit
Merge branch 'parse-errors' of https://github.com/jonathonwalz/Fitbit.NET into jonathonwalz-parse-errors

Conflicts:
	Fibit.Tests/UserTests.cs
	Fitbit.IntegrationTests/UserTests.cs
Merge branch 'jonathonwalz-parse-errors'