support patches documented in the git commit log

My preferred workflow with patches is to just commit them with a standard format for the commit message. Then it's easy to see the list of applied patches to a module by doing a git log of the module folder. (See my write-up of this on github for more details: https://github.com/joachim-n/git-house-guidelines)

It would be nice if this module could check the git log for patch commits.