- added tracker_url to most of the current scripts in release, 
  see http://lists.blender.org/pipermail/bf-blender-cvs/2010-May/028285.html
- apparently missing tracker pages for 2 scripts:
		- io_anim_camera.py
		- io_mesh_stl.py
- wiki links:
	- added link to space_view3d_materials_utils.py
	- conformed link in import_scene_unreal_psk.py

collections like context.selected_objects no longer return None for empty lists. Update scripts for this.
also removed check for obj.data == None for a mesh. This will never happen.

Temporarly using custom py context to apply a modifier now. will change that when there's a better method available.

added pep8 updated wiki link.

[[Split portion of a mixed commit.]]