Update libotr and pidgin-otr to 4.0.0
The main new features in 4.0.0:
* Support v3 of the OTR protocol
* The plugin now supports multiple OTR conversations with the same buddy
who is logged in at multiple locations. In this case, a new OTR menu
will appear, which allows you to select which session an outgoing
message is indended for. Note that concurrent SMP authentications with
the same buddy who is logged in multiple times is not yet supported
(starting a second authentication will end the first).
* During a private conversation with a buddy, an incoming unencrypted
message will now trigger the regular incoming message notifications.
In Pidgin this includes showing the message in the top-right
notification area, if it is normally configured to do so.
* When a private conversation begins, the plugin will indicate whether
Pidgin is configured to log the conversation.
* By default, OTR conversations will not be logged by Pidgin.
* New translations.
* libotr API changes:
- instance tags, to support multiple simultaneous logins
- support for asynchronous private key generation
- the ability to provide an "extra" symmetric key to applications
(with forward secrecy)
- applications can supply a formation conversion callback if they do
not natively use XHTML-style UTF8 markup
- error messages formerly provided by libotr are now handled using
callbacks to the application, for better i18n support
- otrl_message_sending now handles message fragmentation internally