I have a single small change I'd like to submit for integration into the master branch, against JIRA ROO-3083. Do I really need to fork a new branch? The instructions in the source readme.txt assume that you are a project committer I think. I use git version 1.7.10.msysgit.1. I set the global user.name and user.email, but that is for SSH rather than github.

This looks correct:
$ git remote -v
origin https://github.com/SpringSource/spring-roo.git (fetch)
origin https://github.com/SpringSource/spring-roo.git (push)

I committed the changes locally, but on 'git push origin' I got:
Username for 'https://github.com':
Password for 'https://bobfields@github.com':
error: The requested URL returned error: 403 while accessing https://github.com/
SpringSource/spring-roo.git/info/refs
fatal: HTTP request failed

Which means that I don't have rights to commit to the master branch, as expected, even though I typed the correct github user and password. I had hoped this would have shown up as a push request to be approved by a committer.

Is it possible to create and submit a .patch file, like in SVN? Do I need to fork a branch and create a pull request, no matter how small the change? Or is there something else to be changed in the project configuration?