Fix windows paths.
Windows portable icon by forum member Duda.
Portable header & welcome images from forum member Aubergine.
Image fixes supplied by Berg.
Note: In configure stage (Windows only!), you can specify --enable-portable [default no] to
create a portable installer. (That is, everything is self-contained in the directory
you install Warzone 2100 to. It will *not* use any other directory on the system.)
If you pass --with-videos [default no], then it will add the videos with the portable
installer and looks for the video file in \opt\sequences.wz
FIXME: Need: RUSSIAN, GERMAN, DUTCH, tranlations fixes for the warzone2100.nsi file.
vexed