Remove obsolete README.release

Signed-off-by: Jens Georg <mail@jensge.org>
acl: Remove extra references on context/service

Signed-off-by: Jens Georg <mail@jensge.org>
gupnp-service-proxy: remove subscription timeout on subscribe

We have seen crashes in subscription_expire() where user_data
pointed to invalid memory. I do not see an obvious way how this
can have happened, but it seems like a good idea to always
remove the subscription timeout when sending a new subscription
request.

Signed-off-by: Sven Neumann <neumann@teufel.de>