Fix Resource bug that masked the url from ReviewBoard's Web API.

The 'url' attribute in Resource pointed to the Web API resource instead of the
web page.

Testing done: Unit tests pass.

Reviewed at https://reviews.reviewboard.org/r/4899/
Add option to rbt patch for automatically creating a Git commit

The option -c, --commit automatically creates a commit in the current local
branch with the summary, description, bugs, testing, and author information
fetched from the review request.

Testing done:
Tested with a new review request using the commands 'rbt patch -c
<review_request_id>' and 'rbt patch --commit <review_request_id>'.

Unit tests passed.

Reviewed at https://reviews.reviewboard.org/r/4865/