Drop support for python 3.1.

for building py3.2 on *nix see:
  http://wiki.blender.org/index.php?title=Dev:2.5/Doc/Building_Blender/Linux/Troubleshooting#Python

also fixed possible buffer overrun with getting the fake filepath for a blender textblock.

release/scripts/ui/space_userpref.py

@@ -1089,8 +1089,7 @@ class WM_OT_addon_install(bpy.types.Operator):
         addon_path = ""
         pyfile_dir = os.path.dirname(pyfile)
         for addon_path in addon_utils.paths():
-            # if os.path.samefile(pyfile_dir, addon_path):  # Py3.2 only!, upgrade soon!
-            if (hasattr(os.path, "samefile") and os.path.samefile(pyfile_dir, addon_path)) or pyfile_dir == addon_path:
+            if os.path.samefile(pyfile_dir, addon_path):
                 self.report({'ERROR'}, "Source file is in the addon search path: %r" % addon_path)
                 return {'CANCELLED'}
         del addon_path