Breakup xmonad.hs to modules

I had a little trouble finding the docs for how to do this but received
help from the irc channel. xmonad expects modules to live in the folder
`lib/`, ie. `~/.xmonad/lib/`, but to be imported as though they lived
next to `xmonad.hs`.
Merge pull request #4 from steventlamb/topic/dynamic_xmobar_config

Breakup xmonad.hs to modules