Blender's import function check's the Text datablocks in main for additional modules for importing. However, libloaded scenes were 1) not loading Text datablocks and 2) not letting bpy know about them. Text datablocks are now loaded if a Scene is loaded and bpy can now looking through extra Mains to find additional modules.
having the blend file as a part of the __file__ variable is not essential, this is fixed in python 3.2 so add an ifdef and don't use the blend file path for py older then 3.2.
now addon path is created using the same path functions and selecting where to save the startup.blend
also made some minor changes to path handling funcs.
The BGE was getting the namespace dict directly from __main__ which conflicts
with my recent fix to get the pickle module working which to overwrote the __main__ module on script execution.
Simple fix is to have the BGE and Blender use the same method of getting namespaces.
Renamed CreateGlobalDictionary() to bpy_namespace_dict_new() and moved into bpy_internal_import.c
pickle still wont work in the BGE since we make a copy of __main__ namespace but for speed would rather not have to replace the __main__ module many times per second.
* Mathutils, Geometry, BGL, Mostly working, some //XXX comments for things to fix with py3
python import override (bpy_internal_import.c) so you can import python internal scripts from the BGE and running blender normally.
