Tweaked: Ground unit limits

* Added: Script to delete empty choppers which are left on the resupply areas for more than 3 minutes.
* Added: Server log debug output.
* Added: Mapmarker in the bottom left with server fps and ground units count.
* Added: 2 Spectator slots.

KNOWN ISSUE:
When a helicopter gets deleted at a resupply area, a radio message with "helo down" will be send.
But this won't lower your tickets. It's just a kind of misleading information which I can't deactivate for now.

Fixed: Players where able to capture a sector.