A.CycleWindows replace partial rotUp and rotDown with safer versions
A.CycleWindows replace partial rotUp and rotDown with safer versions

Ignore-this: 6b4e40c15b66fc53096910e85e736c23
Rather than throw exceptions, handle null and singleton lists, i.e.
f [] gives [] and f [x] gives [x].

darcs-hash:20100123231912-18562-6986c6acb711331ab135e62e1a41fbe8aabf5f13

jthornber/XMonadContrib,jthornber/XMonadContrib