mpris: Force refetching of Position property

Position is not supposed to be notified, so for some clients
GDBus does not update the cache although it changes.

We invalidate the cache here so that it will always be re-fetched
from the peer.

Signed-off-by: Jens Georg <mail@jensge.org>
mpris,external: Fix plugin activation

Signed-off-by: Jens Georg <mail@jensge.org>
examples: Fix renderer example

Signed-off-by: Jens Georg <mail@jensge.org>
examples: Set license of GI examples to BSD

Signed-off-by: Jens Georg <mail@jensge.org>
mpris: Trigger status update on connection

Signed-off-by: Jens Georg <mail@jensge.org>
server: Call the base class in apply_didl_lite

Otherwise the didl lite is not applied to the parents members.

https://bugzilla.gnome.org/show_bug.cgi?id=737867
Prepare 0.24.1

Signed-off-by: Jens Georg <mail@jensge.org>