Drop support for user-defined data since this capability was not used
so far and GstVaapiMiniObject represents the smallest reference counted
object type. Add missing GST_VAAPI_MINI_OBJECT_CLASS() helper macro.
Besides, since GstVaapiMiniObject is a libgstvaapi internal object, it
is also possible to further simplify the layout of the object. i.e. merge
GstVaapiMiniObjectBase into GstVaapiMiniObject.
Use GPOINTER_TO_SIZE() instead of GPOINTER_TO_UINT() while manipulating
pointers. The latter is meant to be 32-bit only, not uintptr_t like size.
Only a gsize can hold all bits of a pointer.
Thanks to Ouping Zhang for spotting this error.
Introduce a new reference counted object that is very lightweight and
also provides flags and user-data functionalities. Initialization and
finalization times are reduced by up to a factor 5x vs GstMiniObject
from GStreamer 0.10 stack.
This is a libgstvaapi internal object.
