added a regex-message-filter. It will take a (or more) regex and remo…

[erik-romson]

…ve everything in the commit message that doesn't match with the regex

Hi, I want to be able to tell downstream users what is currently running on our service. therefore I want to give them access to the changelog, containing only jiraissues-ids that they can check in an browser.

I have added a possibility to remove everything from a commit message apart from whatever matches the given regex

see changed and added tests for an overview

Hope that you will find this good enough to be merged, /erik