Commit messages are now additionally truncated after the first line.
Before, a commit message's body was attached behind the subject which
made messages hardly readable in some cases.

Replaced .show and .hide with .removeClass('hide') and .addClass('hide') (Like done for #192 in MR 177)

- check if user has manage access to project
- don't cache result of authorized_projects, because it's serialised with User object
- clear user sessions

Disable link to runner if it's not assigned to specific project: fixes 404 when clicking on available runner from project's page

It allows to ignore status of specific job when computed for commit