Merge pull request #39 from Earnestly/master

man: Document WLC_BG and WLC_DEBUG environment variables.
Use mod-j, k to cycle clients

* Move output cycling to mod-l
* Update documentation
Merge pull request #40 from holomorph/mod-jk

Use mod-j, k to cycle clients
Update image
Update wlc
Update wlc.
Update wlc.
Update wlc.