Rough stub of mod_bosh
Finalize module/listener startup compatibility
Start connection negotiation
Start work on BOSH backends
Extract mod_bosh_socket

A process persistent throughout the BOSH session lifetime is necessary
for c2s to send messages to. It interfaces with c2s as though it was a
socket but communicates with the client using Cowboy's loop request
handlers.
Add mod_bosh listener to ejabberd.cfg
Add BOSH session cleanup
Make the supervisor name console/typing friendlier
More error handling
Add NS_HTTPBIND namespace macro
Convert session creation request to stream start
Add notice
Add mod_bosh <-> c2s <-> socket forwarding logic
WIP: wrap/unwrap
Make BOSH socket intermediate between cowboy handlers and c2s
Add change_shaper/2 no-op
Simplify mod_bosh - let socket do the heavy lifting
Work on connection initiation
Convert bosh_socket to a gen_fsm
Leave state 'accumulate' after timeout