Deprecate {begin,send}_action_hash

They cannot guarantee the order of arguments which breaks interaction with
DLNA-complient devices.

The use of end_action_hash is fine, though. It can be paired with all of the
begin_action_* functions.

https://bugzilla.gnome.org/show_bug.cgi?id=710491
Add deprecation guards
Add gupnp_service_info_get_introspection_async_full()

This version of get_introspection can be cancelled using GCancellable.

https://bugzilla.gnome.org/show_bug.cgi?id=704867
tests: Add a way to test cancelling introspection gets

First ctrl-C in test-introspection will cancel all current and future
gupnp_service_info_get_introspection_async_full() calls.

https://bugzilla.gnome.org/show_bug.cgi?id=704867
Revert "tests: Add a way to test cancelling introspection gets"

This reverts commit c90f519475e3c710128454188f5c3e5c3ad62ee0.
Revert "Add gupnp_service_info_get_introspection_async_full()"

This reverts commit 909e721c52a335aa8b0ef8f3c37fa62216451530.
Add gupnp_service_info_get_introspection_async_full()

This version of get_introspection can be cancelled using GCancellable.

https://bugzilla.gnome.org/show_bug.cgi?id=704867
tests: Add a way to test cancelling introspection gets

First ctrl-C in test-introspection will cancel all current and future
gupnp_service_info_get_introspection_async_full() calls.

https://bugzilla.gnome.org/show_bug.cgi?id=704867