Update README.md for testrel

- `make devrel` does not generate testing nodes
  switching to `make testrel`
Change terminate/2 to terminate/3 for cowboy master
add some comment on creating callback that this is a huge TODO
add type definitions to records used
Merge pull request #63 from l4u/patch-1

Update README.md for testrel
Merge pull request #65 from l4u/patch-3

Change terminate/2 to terminate/3 for cowboy
Adjust mod_websockets to new cowboy routing scheme
Make mod_websockets resilient to multiple starts

When ejabberd is configured to serve multiple domains (e.g. localhost
and anonymous.localhost) the module is started once for each served
domain.

This caused a badmatch when doing cowboy:start_http for the second and
consequent times.
Update required Erlang version in README.md

`callback` attribute used by some deps is available only since R15B.
Fix (un)packing in mod_muc_room (string leftovers)
Fix MUC room name check
Fix integer value submission in form in MUC
Fix string:len call in mod_muc_room
Define binary_to_integer (only) if unavailable
Reduce binary_to_integer and back code duplication
add some more comments
no websockets for me please
add some more comments
Merge remote-tracking branch 'mainline' into mod_webhooks

Conflicts:
	rel/files/ejabberd.cfg
add hook for authentication