Replaced multiple get_review_request methods with an equivalent utility function

Review Request #6348 — Created Sept. 20, 2014 and submitted — Latest diff uploaded

Information

RBTools
master
8f14536...

Reviewers

There was a method called get_review_request() in 4 different classes with identical
bodies. They have now been replaced with a utility function in rbtools.utils.commands.

Manually tested attach, close, post, publish commands.

It seems difficult to add new unit tests to verify the correctness of this new
change. And the existing unit tests pass even if the commands are fatally broken.