[CF-Devel] exit changes checked in.

[Mark Wedel]

 From my testing, this appears to fix the pocket realities as well as the word
of recall to unique maps:

MSW 2001/02/06:
common/porting.c: relocate clean_path from this file to server/main.c
server/main.c: relocate clean_path from porting.c.  Add unclean_path.
    Modify enter_unique_exit so it supports relative maps on unique maps.
    Modify enter_exit so word of recall (or other forcelike fields), work
    when the return point is a swapped out unique map.