#3 basic volume controls

[Joshua Heling]

This patch adds "vol+" and "vol-" controls to the
navbar, which implement implement a relative volume
change via the Audio::Mixer perl module.

In order to work, the otto process must have write
perms on /dev/mixer - this is as easy as 'chgrp apache
/dev/mixer; chmod g+w /dev/mixer' (or equivalent,
depending on the runtime environment particulars).

[Joshua Heling]

simple volume control patch