Backend for editing source check flags

Issue #540

Signed-off-by: Michal Čihař <michal@cihar.com>
Text based editing of source check flags

Issue #540

Signed-off-by: Michal Čihař <michal@cihar.com>
Add link to the documentation

Signed-off-by: Michal Čihař <michal@cihar.com>
Perform flags validation on save

Issue #540

Signed-off-by: Michal Čihař <michal@cihar.com>
Remove no longer used javascript variables