[patch] do not segfault when D-Bus connection is reused

[Havoc Pennington]

Havoc Pennington wrote:
> 
> Well, they have different semantics. close() absolutely requires an 
> "owner" - it's something that inherently can be done only once, and has 
> side effects affecting everyone using the connection. So for any 
> connection, if you want to close() it, you have to be able to say "this 
> part of the code owns whether/when to close it, and nobody else is allowed"
> 

btw, for shared connections I think the owner is basically libdbus, and 
eventually there might be a "garbage collection" - e.g. after a timeout 
we kill the connections.

Havoc