Do not leak internals of SpiceUsbDeviceWidget in public headers. This makes also
the class final, which let us extend more easily without fear of breaking ABI.
Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Acked-by: Fabiano Fidêncio <fidencio@redhat.com>
This header is the single include needed for all gtk-related
functionality, similar to spice-client.h. Generate a compiler warning if
a different header is included.
