Replaced old "spawn on mod+s" semantics with "spawn/summon or banish on mod+s".
Replaced old "spawn on mod+s" semantics with "spawn/summon or banish on mod+s".

Originally the key binding just spawned a new floating terminal on every keypress.
Now it spawns if it doesn't exist, summons from another workspace if it does but
isn't visible, or banishes it to a dynamically created workspace if it is on the
current workspace.

darcs-hash:20080608045457-d53a8-e8bca6a987f7f408c18481d2173dd2f87a8d40fb

kmels/xmonad-launcher,kmels/xmonad-launcher