This piggy backs onto the previous changes for protocol 22 and
thus does not bump the version. This and the previous commits should be
seen as mostly atomic. Apologies for any bisecting issues this causes
(although I would expect these to be minimal)
This adds a PA_VOLUME_IS_VALID() macro for checking if a given
pa_volume_t is valid. This makes changes to the volume ranges simpler
(just change PA_VOLUME_MAX, for example, without needing to modify any
other code).
* Make the dbus object constructors take a pa_dbusiface_core pointer
as an argument. Remove the path_prefix argument.
* Expose the core object path as a constant in protocol-dbus.h.
* Move the core interface name constant from iface-core.h to
protocol-dbus.h.
