Improvements to pulseaudio

- Add a DEBUGGING flag
- Make the location of the unix socket configurable

While I was here I moved all the priority configs in supervisord to the top. I like it better there

overlay/etc/supervisor.d/xvfb.ini

@@ -1,8 +1,8 @@
 
 [program:xvfb]
+priority=20
 autostart=false
 autorestart=true
-priority=20
 user=root
 command=/usr/bin/Xvfb %(ENV_DISPLAY)s -screen 0 "%(ENV_DISPLAY_SIZEW)sx%(ENV_DISPLAY_SIZEH)sx24"
 environment=DISPLAY="%(ENV_DISPLAY)s"