Python API

made all libdata hashable - use the object type,name and lib for the hash.
added .tag to libdata so we can test if data's been processed without using dictionaries
added libdataseq.tag (write only) setting the tag flag (which can always be dirty)

source/blender/python/api2_2x/Image.c

@@ -1324,7 +1324,7 @@ PyTypeObject Image_Type = {
 
 	/* More standard operations (here for binary compatibility) */
 
-	NULL,                       /* hashfunc tp_hash; */
+	( hashfunc ) GenericLib_hash,	/* hashfunc tp_hash; */
 	NULL,                       /* ternaryfunc tp_call; */
 	NULL,                       /* reprfunc tp_str; */
 	NULL,                       /* getattrofunc tp_getattro; */