OBJ exporter working (Python 3.0), but needs testing and fixing.

Current issues:
- NURBS - needs API additions
- "all scenes" export - cannot switch scene in bpy
- normal calculation, disabled
- duplis - need testing, only dupliverts tested
- matrix problem
- UI, 18 options currently don't fit into filesel panel, will do manual lay out once it's available
- probably others...

BPY:
- made operator "execute" method required to avoid crash
- added bpy.sys module which replicates old "sys" module

API:
- replaced create_*_mesh with a single create_mesh accepting type parameter
- added Mesh.create_copy to create a copy of a mesh with 0 users

Ran `dos2unix` on source/blender/python/SConscript

source/blender/python/intern/bpy_interface.c

@@ -19,6 +19,7 @@
 #include "bpy_rna.h"
 #include "bpy_operator.h"
 #include "bpy_ui.h"
+#include "bpy_sys.h"
 #include "bpy_util.h"
 
 #include "DNA_anim_types.h"
@@ -91,6 +92,7 @@ void BPY_update_modules( void )
 	PyObject *mod= PyImport_ImportModuleLevel("bpy", NULL, NULL, NULL, 0);
 	PyModule_AddObject( mod, "data", BPY_rna_module() );
 	PyModule_AddObject( mod, "types", BPY_rna_types() );
+	PyModule_AddObject( mod, "sys", BPY_sys_module() );
 }
 
 /*****************************************************************************