- registerTextCommands can be called by a plugin in its __init__ method, it looks for methods starting with "cmd_" and register them as new commands
- addWhoIsCb: add a callback to /whois command, the callback can complete whois informations
- plugins parrot, XEP-0045 and XEP-0092 now manage their own commands
- _() is no more installed in __builtin__
- instead, there is a new sat.core.i18n module
- added D_() method for deferred translation
- languageSwitch method allow to dynamically change translation language
- import gettext is tested against ImportError, and dummy methods are used when not available (mainly useful for Libervia)
- treaments deferred can be used by plugins to change XML elements before sending them, in a similar way as for newMessage
- sendMessageXml trigger became useless, so it as been removed in favor of the new deferred
onMessage now use a deferred which is passed to MessageReceived trigger through the post_treat parameter. This can be used by plugins to add deferred in the callback chain.
- sendMessage now use JID instead of unicode, bridge method using unicode is now _sendMessage
- added no_trigger argument, so it's now possible to forbid trigger execution (to avoid any plugin when we send a message)
