When a room is flagged TRANSIT, the character is no longer
realy in the room as far as he can see.

Transit rooms cannot be exited normally, and cannot be treated normally.
To cheat, variables are stored in extra_descr.
The variable names all start with 0 to lessen the chance of players
hitting upon them with a missed abbreviation.
Variables:
0TRANSITSPEED - How many mini-ticks it takes for the transit to move.
0TRANSITNAME  - Sets the short name of the transit. "The $n moves north"
		where shortname would be $n
0TRANSITSCHEDULE - This one is complex.
	A mini-tick is every 5 seconds.