Dockapp mixer for OSS or ALSA.

Allows toggling record source, muting individual channels, adjusting
volume and balance, all in a compact dockapp size, with TV-like
on-screen-display for volume levels.  Supports mousewheel to adjust
current channel volume, and can be controlled remotely with SIGUSR1 /
SIGUSR2 to adjust the volume, too.  Can use a configuration file to
control some of the features.
