U.Scratchpad: add general spawn action to close issue 249
U.Scratchpad: add general spawn action to close issue 249

Ignore-this: 925ad9db4ecc934dcd86320f383ed44a
Adds scratchpadSpawnActionCustom where user specifies how to set
resource to "scratchpad". This allows use of gnome-terminal, etc.
Add detail to RationalRectangle documentation; strip trailing spaces.

darcs-hash:20090214003642-d17f0-2b2a11617ed0dd4c5dc9fba62ac90373002043f3

yzhou61/xmonad-contrib,yzhou61/xmonad-contrib,yzhou61/xmonad-contrib