Handle these 2 kinds of script paths
* user script path: ~/.blender/scripts OR $BLENDER_USER_SCRIPTS
* pref script path: always bpy.context.user_preferences.filepaths.script_directory
now both are returned by bpy.utils.script_paths()
we cant ensure buildinfo to have utf8 encoding so access it as bytes via python - a different workaround then this patch made.
also use C style string formatting for sys_info.py