XPrompt: fixes a nasty bug in getLastWord
XPrompt: fixes a nasty bug in getLastWord

This patch fixes a nasty bug in getLastWord, a bug that causes XMonad
to crash as soon as the command line consists of only 2 empty spaces.
*PLEASE UPDATE* if you are running XPrompt.

darcs-hash:20070815163457-32816-13dc80cfb1fccaca6717df60072f2d3e9fc68bf7

kmels/xmonad-launcher,kmels/xmonad-launcher