Fix for missing X11 libraries in Leopard

This solution comes straight from: Penny Smalls.. I've just put it here for personal reference.

dyld: NSLinkModule() error
dyld: Library not loaded: /usr/X11R6/lib/libdpstk.1.dylib
  Referenced from: /usr/local/lib/ruby/gems/1.8/gems/rmagick-1.15.9/lib/RMagick.bundle
  Reason: image not found
Trace/BPT trap

Those dylib files do not exist any more. But… I have a backup (I hope you do). I ended up doing this:

cd /Volumes/BackupDisk/usr/X11R6/lib
sudo cp libdps*1.0* /usr/X11R6/lib/
sudo ln -s /usr/X11R6/lib/libdpstk.1.0.dylib /usr/X11R6/lib/libdpstk.1.dylib
sudo ln -s /usr/X11R6/lib/libdps.1.0.dylib /usr/X11R6/lib/libdps.1.dylib