Now room owners are able to set a preferred language
for the discussions in the room, so other users can
discover rooms based on the language they wish to talk.
TODO: the language format should conform to RFC 5646.
This check should be implemented in 'xmpp' library.
Fixes#2436
Now 'muc#roominfo_contactjid' and 'muc#roominfo_pubsub' fields
are returned within muc#roominfo form. Also, both 'muc#roominfo_pubsub'
and 'muc#roomconfig_pubsub' are now validated.
It's now possible to use files as internal packet queues.
The following options are introduced:
* queue_type: the option can be set to `ram` (default) or `file`.
The option can be set per virtual host.
* queue_dir: path to the directory where queues will be allocated.
The default is 'queue' directory inside Mnesia directory.
This is a global option and cannot be set per virtual host.
Use dynamic Rebar configuration
Make iconv dependency optional
Disable transient_supervisors compile option
Add hipe compilation support
Only compile ibrowse and lhttpc when needed
Make it possible to generate an OTP application release
Add --enable-debug compile option
Add --enable-all compiler option
Add --enable-tools configure option
Add --with-erlang configure option.
Add --enable-erlang-version-check configure option.
Add lager support
Improve the test suite
