Improve Console Commands

[rgrieder]

There are currently some issues and missing feature with console commands. I would like to compile a list here that can be discussed and modified:

1. Activity: Console commands should have the possibility to be active/inactive
2. Lifetime: Console commands should be destructible and therefore more dynamic
3. Accessibility: Console commands should have access permissions.
4. Dispatching: What about console commands that can be applied not to one single static function but to all objects of a member function? It would be almost like the config values but with 5 possible different arguments and no ini-file entry.

There is already some basic construct to realise accessibility but it is not yet implemented. I think this might be quite important because sometimes these console commands ease programming by magnitudes if you want to avoid some singleton-hacking or so.

Btw: I assigned the severity of the ticket "critical" because we currently have memory leaks due to console commands.