Enhancements to xcap_pres_rules script

darcs-hash:20081026153743-1e3d8-406c7affe21253b43071697556acb17791125d86
Make installer also consider xcap_ scripts

darcs-hash:20081026153821-1e3d8-6e9905a04d40cfff4865a631a2d313f08ecfe7e3