Minot design changes; add a template function for short commits
Do not override the repo object in pull-requests

This way it displays the repo against which the pull-request was made,
it does not switch to the repo from which the pull-request originated
Fix showing the diff of a pull-request that the p-r is opened or closed

fixes #12
Set a Message-Id in addition to the mail-id header

Relates to #13
The message-id should be in between <>
Let's not convert the content to unicode