bindings/pyduplex: initial implementation of pydpx
bindings/pyduplex: more fixes, but segfaults

Needs investigating into how ctypes returns a pointer that we
can use later (from dpx_peer_new(), because bind fails).
bindings/pyduplex: fix basic sending/receiving of frames
bindings/go-duplex: add support for switching codecs
bindings/pyduplex: finish all tests for pydpx (passing!)
Merge branch 'dev_libtask_again'

Closes #2
README: pydpx is a thing now
libdpx: when closing a channel, yield to allow other tasks to finish

this also fixes go-duplex bindings as a result.
libdpx: if peer fails to accept from bind try again

If it fails again there's nothing we can do...
libdpx: make latency tests based off of zeromq
Merge branch 'master' into dev_nosockets

Conflicts:
	libdpx/dpx.c
libdpx: more changes