JEP-85 (Chat States) + Fixes

Hi,

I implemented JEP-0085 (Chat States) for PyMSN-t. This is the  
standards-track JEP for typing notifications, and is used by clients  
such as Google Talk, Gajim, and the next version of Psi. The way I  
implemented it, PyMSN-t will not send or request the old type of  
message events initially, but if it detects that the Jabber client  
only supports the legacy protocol, it will switch to that one. The  
patch can be found here:
        http://el-tramo.be/files/pymsn-t/chatstates.diff

While implementing this, i stumbled upon a bug in the composing  
handling. Whenever the MSN contact sends a message while he was  
composing, the internal 'composing' state is not reset. This means  
that if the contact starts composing again, MSN-t will not send a new  
composing event to the Jabber side until the timeout period expires  
(and the composing event is canceled). I fixed this here:
        http://el-tramo.be/files/pymsn-t/composing_fix.diff

Finally, calling /usr/bin/python doesn't work on systems that don't  
have python in that location (such as my Mac, where python is in /sw/ 
bin). I think the clean way of handling this is to change the shebang  
in PyMSN-t into
        #!/usr/bin/env python
which i do in this patch:
        http://el-tramo.be/files/pymsn-t/shebang_fix.diff

cheers,
Remko