[MERGE] Fix the dbus plugin by changing the SmartServer hooks API.

[Vincent Ladeuil]

Vincent Ladeuil has voted +1.
Status is now: Approved
Comment:
Even clearer than the first discussion on the mailing list.
Not deprecating the hooks signatures ? Ok, for this time considering 
it's mentioned in LIBRARY API BREAKS :)
I like the chroot implementation.
Please merge with comment fixes mentioned by Martin. I'm fine with 
external_url name, the doc string is very clear.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C1183603227.15211.113.camel%40localhost.localdomain%3E