sound support

[Antoine Martin]

What we have there kinda works, but there are many issues that need improving/resolving:

• we must use pactl to setup the tcp socket we're going to forward (was hacked together with 'socat')
• maybe try to forward the local file socket instead of a tcp socket (using ssh - won't work with putty...)
• there seems to be different ways of configuring pulseaudio on the client, some people have the systemwide daemon, etc.. ensure this all works.
• bandwidth: pulseaudio's TCP protocol is a bandwidth pig... We must ensure we only use it over fast links (need better detection?)