Major bugfixes and reworked the code to make more sense.

Methods now always return false when they don't work.
HTTP status codes are available in $this->status
Human readable error messages are available in $this->error
Full response is available in $this->response
Raw response (JSON) is available in $this->raw_response
Errors are now properly handled if cURL runs into a problem (e.g. can't resolve hostname)