One place to generate KILL query

Signed-off-by: Michal Čihař <michal@cihar.com>
Avoid double conditions for DELETE_ROW/KILL_PROCESS, handle all of that in _getDeleteAndKillLinks

Signed-off-by: Michal Čihař <michal@cihar.com>
Make _addClass a bit more readable

We now construct an array which we join in the end. This avoids need to
care about spaces in the class names.

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