- pw_core_info has data that represent the remote core
- pw_core properties are the properties of its pw_client,
initially inherited from the pw_context, which can be updated either
when calling pw_context_connect() or later at runtime (the pw_core
calls pw_client_update_properties() on its pw_client)

wp_core_update_properties() is made in such a way so that we can do:
```
clone = wp_core_clone(core);
wp_core_update_properties(clone, ...);
wp_core_connect(clone);
```
and get clone to have different properties than the original core,
while they still share the same pw_context underneath

also delay the "connected" signal until info is there

a method to take the internal pw_properties without copying

and do not allow writing to wrapped pw_properties,
since they are const now

    - due to usage of Reference-counted-data in lib/wptoml/array.cpp
      (requires >= 2.58, see https://developer.gnome.org/glib/stable/glib-Reference-counted-data.html)
    - and usage of G_GNUC_FALLTHROUGH in lib/wp/object-interest.c
      (requires 2.60, see https://developer.gnome.org/glib/stable/glib-Miscellaneous-Macros.html#G-GNUC-FALLTHROUGH:CAPS

)

Signed-off-by: Martin Koch, ESE GmbH <martin.koch@ese.de>

the spa object undereath doesn't do that and we lose a bunch of
properties otherwise

By mistake, WpImplNode was developed by keeping in mind that the proxy
returned by pw_core_export() is a PW_TYPE_INTERFACE_Node, but this
is not true. It's actually a ClientNode...

Unfortunately, making WpImplNode work as if it was a WpNode is
not so easy, especially when it comes to handling params, which
need to be queried syncrhonously on the underlying spa_node.

So, instead of fixing WpImplNode to work as a WpNode, we choose to
disconnect them. This way, WpImplNode will not be used as a proxy
in the registry and the registry will normally create WpNode proxies
instead, making round-trips through the server to change node params.

reserve-device: don't increment jack_n_acquired if it is 0 and use the updated value when setting data

if jack is running, that probably means that we want the jack
endpoints to be the default playback/capture path

This is necessary to finish augmenting nodes that advertise
PropInfo & Props in their param info but they don't actually have
any properties, so there is no param event emitted
(ex. the jack device nodes)

Because the sync is synchronous with the calls over the protocol,
the callback is ensured to be called after all the param events
have been emitted