[WIP] Custom footer for email messages
I have a requirement to include some text at the bottom of emails sent by GitLab. Currently I'm using the changes here to cover most instances I think in GitLab 7.10 but there are a couple of areas I may be missing.
Things I think need to be worked on:
- Configuration should be in the database and not gitlab.yml
- Add setting to admin page
- Ensure that all emails are covered
- HTML / plain text
- Documentation