Make setbg behave closer to how feh does
Add `off-the-record` function to zsh

This commit also moves the blue R: indicating that ranger is running to
before the PWD, so that OTR: can be displayed before the prompt.
Change xmonad ardour-mixer layout

I no longer use the "audio connections" window in the side pane, so
there is no need for two different pane sizes.
Clean up zsh prompt customization; make user blue
Add youtube-dl alias for downloading mp3 files