Version 2.9.4 checkin.

Version 2.9.4 checkin.
- Merged popupfile and cookiefile, and added control over PCRS
  filtering, in new "permissionsfile".
- Implemented LOG_LEVEL_FATAL, so that if there is a configuration
  file error you now get a message box (in the Win32 GUI) rather
  than the program exiting with no explanation.
- Made killpopup use the PCRS MIME-type checking and HTTP-header
  skipping.
- Removed tabs from "config"
- Moved duplicated url parsing code in "loaders.c" to a new funcition.
- Bumped up version number.