Do not talk about git

Signed-off-by: Michal Čihař <michal@cihar.com>
Block online change of a vcs

This could work, but the problem is that before changed object is saved
the linked repos still see old vcs leading to horrible mess.  Changing
vcs from the manage.py shell works fine though.

Signed-off-by: Michal Čihař <michal@cihar.com>
Fix typo

Signed-off-by: Michal Čihař <michal@cihar.com>
Log error

Signed-off-by: Michal Čihař <michal@cihar.com>
Fix push command

Signed-off-by: Michal Čihař <michal@cihar.com>