A simple web volume controller for OS X v0.2.0

The controller executes applescript to get and set the volume of
Airfoil Speakers. A system audio version is available (although
possibly out of date) as it's own branch (system-audio).

In theory, since we're using applescript you should be able to
integrate with any control within OS X, with minimal changes.

Install instructions:

Mac OS X does not allow the default apache user (_www) to
interact with the window models. Any applescirpt that attempts
to will fail. The fix for this, is to run apache as the user
who will be logged into OS X while the volume control is used.

Although you could use any user, it's probably a bad idea to
use a system administrator account, as any vulnerabilities in
apache could allow an attacker to completely compromise your
system.

The way I run this is by creating a new 'music' user. The user
should not be allowed to administer the machine. Then modify
/private/etc/apache2/httpd.conf so that the user and group lines
that original point to _www to point to:

user music
group staff

This would also be a good time to change your DocumentRoot to
point to the root folder of the git repository you checked out.

DocumentRoot "/Users/jstockdale/Sites"

(NB: Here you see I'm running apache as the music user but the
code is owned by me. In general, it's a good idea for the code to
be cloned by a different user than is running apache, so that a
malicious attacker can't modify the running code unless they do
more than compromise apache.)

Finally, log into the system as your new 'music' user. Go to
'System Preferences' and under 'Universal Access' make sure
'Enable access for assistive devices' is checked. Now start up
Airfoil Speakers, and navigate to http://localhost/volume.php

(You can also use fast user switching, but the music will only
play while the 'music' user is currently active.)

Enjoy!