Ideally IAXmodem would use a small (maybe 20-60 ms) jitterbuffer
to ONLY reassemble audio frames in a proper order rather than 
synthesizing audio, dropping mis-ordered frames, or using them 
mis-ordered.  However, the libiax2 jitterbuffer does not work 
this way.  So that's why the jitterbuffer is disabled.  That said,
jitter never should occur when communicating over loopback, and it
should almost never occur when communicating over an average LAN.
So the application of such a jitterbuffer may actually be limited.

IAXmodem is unable to be used with HylaFAX's pagesend.  The pty
locks up with the setParity attempt during the reset.  This seems
to be somewhat related to the other ioctl limitations imposed
by the openpty usage.  Not sure if this is fixable as long as
openpty is used.  Not sure who to contact about openpty.
