Move to wxWindows done

The program is now using wxWindows. All strings have been converted to use wxString, and DLL support now uses wxDynamicLibrary. The only place using the old C/C++ strings is the error handler, and I don't see much point in messing with that right now.

There's also been some reworking of the DLL support to get a better architecture for the class type handlers.

Three main things left to do now for the alpha: fully implement parallel port handling; add the PIC programming algorithm (probably copying much of it from some other program); and put on a minimal front end.