Python needs to support combined files

[KeyWorksRW]

Description:

In C++, having one class per file is the standard practice. In Python, however, modules often contain multiple classes, as well as functions. We already support a combined file for XRC, so it would make sense to support a combined file for wxPython as well.

Note that folders already have a folder_python_combined_file though I don't think support for this has been implemented yet (it should). That would be the ideal way to handle multiple modules with each folder being a module with as many forms/classes as the user wants in that module.

We only allow the user to add code to the end of the file, so this does mean that a user will need to create an inherited class in order to add event handlers.