bpy/rna api class feature

- python defined classes will be used when available (otherwise automaically generated metaclasses are made as before)
- use properties rather then functions for python defined rna class's
- call the classes getattr AFTER doing an RNA lookup, avoids setting and clearing exceptions for most attribute lookups, tested UI scripts are ~25% faster.
- extending rna py classes this way is a nicer alternative to modifying the generated metaclasses in place.

Example class

--- snip
class Object(bpy.types.ID):

    def _get_children(self):
        return [child for child in bpy.data.objects if child.parent == self]

    children = property(_get_children)
--- snip

The C initialization function looks in bpy_types.py for classes matching RNA structure names, using them when available.
This means all objects in python will be instances of these classes.
Python properties/funcs defined in ID py class will also be available for subclasses for eg. (Group Mesh etc)

release/scripts/modules/bpy_ext/Object.py

@@ -1,22 +0,0 @@
-# ##### BEGIN GPL LICENSE BLOCK #####
-#
-#  This program is free software; you can redistribute it and/or
-#  modify it under the terms of the GNU General Public License
-#  as published by the Free Software Foundation; either version 2
-#  of the License, or (at your option) any later version.
-#
-#  This program is distributed in the hope that it will be useful,
-#  but WITHOUT ANY WARRANTY; without even the implied warranty of
-#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#  GNU General Public License for more details.
-#
-#  You should have received a copy of the GNU General Public License
-#  along with this program; if not, write to the Free Software Foundation,
-#  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
-#
-# ##### END GPL LICENSE BLOCK #####
-
-import bpy
-class_obj = bpy.types.Object
-
-class_obj.getChildren = lambda self: [child for child in bpy.data.objects if child.parent == self]