Rework transport protocol

Remove the old PinosBuffer object and replace it with SpaControl, this
communication protocol is designed to make it possible to implement
remote nodes and so it is moved to Spa.
Move SpaBuffer into to API
Work on easier API to make formats, implement enumeration and support
for all formats in v4l2.
Improve format output in -inspect

spa/plugins/alsa/alsa.c

@@ -40,6 +40,7 @@ spa_enum_handle_factory (const SpaHandleFactory **factory,
     default:
       return SPA_RESULT_ENUM_END;
   }
-  *(int*)state = index++;
+  *(int*)state = ++index;
+
   return SPA_RESULT_OK;
 }