[Shtoom] ringring feature works!

[Zooko O'Whielacronx]

>  * play ring.wav on incoming call and play ringback.wav on outgoing 
> ring
> It's a feature!  It comes with wav files.  Whee!

Note: this only works when there is a nice fat audio output FIFO that 
can store up the whole ring file (approx 1 second).

So on Linux/ALSA, you hear just a blip of a ring instead.

See comments in code (such as by clicking on the patch on my web site) 
to see why.

--Z