refactor(pacman): switch to some more lightweight tools
refactor(pacman): switch to some more lightweight tools

Instead of `gnome-control-center` (massive overkill), use the hideously
ugly but simple `pavucontrol` to control PulseAudio.

Get rid of `caja` (can just live with `pcmanfm` instead; it's ugly, but
it's ridiculously fast and lean).

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent