[2/2] server: Allow multiple registry notifications per key.

[Sebastian Lackner]

On 10.11.2015 23:01, Sebastian Lackner wrote:
> Signed-off-by: Sebastian Lackner <sebastian at fds-team.de>
> ---
> 
> After this patch there are still a couple of remaining problems:
[...]
> * The WatchSubtree Flag and the filters parameter should be stored somewhere in the
>   key object itself? It seems like its not possible to change it anymore after
>   the first notification.

I just saw that this was already working fine in the old implementation, which
means my patch could cause regressions. :( Please ignore this patch for now.
I'll resend 1/2 alone with some more tests.