poll() as a python '@staticmethod' was too limiting and didnt allow useful base class poll functions in many cases.

now rna functions that dont have a 'self' are automatically assumed '@classmethods'.

de-duplicated poll functions and made some minor tweaks too.

release/scripts/ui/properties_scene.py

@@ -26,8 +26,8 @@ class SceneButtonsPanel():
     bl_region_type = 'WINDOW'
     bl_context = "scene"
 
-    @staticmethod
-    def poll(context):
+    @classmethod
+    def poll(cls, context):
         return context.scene
 
 
@@ -44,6 +44,7 @@ class SCENE_PT_scene(SceneButtonsPanel, bpy.types.Panel):
 
 
 class SCENE_PT_custom_props(SceneButtonsPanel, PropertyPanel, bpy.types.Panel):
+    COMPAT_ENGINES = {'BLENDER_RENDER', 'BLENDER_GAME'}
     _context_path = "scene"
 
 
@@ -108,8 +109,8 @@ class SCENE_PT_keying_sets(SceneButtonsPanel, bpy.types.Panel):
 class SCENE_PT_keying_set_paths(SceneButtonsPanel, bpy.types.Panel):
     bl_label = "Active Keying Set"
 
-    @staticmethod
-    def poll(context):
+    @classmethod
+    def poll(cls, context):
         return (context.scene.active_keying_set and context.scene.active_keying_set.absolute)
 
     def draw(self, context):