[sugar] add xcompmgr to the olpc-development stream builds

[Bernie Innocenti]

Marco Pesenti Gritti wrote:
> I'm trying to stay more or less consistent with the separation between
> DM and desktop session, for practical reasons (Sugar needs to work
> fine if runned from gdm, for example).
> 
> olpc-session is the equivalent of a DM, so I don't think it should run
> the window manager, nor the composite manager.

Good point, I agree.

-- 
   // Bernie Innocenti - http://www.codewiz.org/
 \X/  Sugar Labs       - http://www.sugarlabs.org/