FMSLogo Code

Update the screensaver's Makefile to use the mingw-w64, instead of the older mingw.org compiler. This is being done to standardize on a single compiler, which will hopefully make building FMSLogo simple enough that other people will try.

Unfortunately, the mingw-w64 suite has an empty libscrnsave.a, so upgrading the compiler required adding source code that should have been included in the library. The scrnsave.c file is copied directly from the mingw-w64 source tree with an "#if 0" removed. If mingw-w64 eventually has a functional libscrnsave.lib, this file should be removed.

Fix some build breaks when compiling the "msdbg" screensaver, which uses the Microsoft SDK compilers. These were introduced in the recent header file refactoring to remove assembly.h and main.h.

Remove assembly.h and main.h. These header files exited to support a defunct instruction set (assembly.h) or the defunct OWL FMSLogo (main.h). Neither of these two things will be supported going-forward, so I'm removing the vestigial header files for general cleanup.

Because these header files were included by many source code files, removing the header files required a lot of header file refactoring.

Remove the Borland OWL version from the build.
Now that the wxWidgets is the mainline version and is stable, the Borland OWL code only slows down development.

Remove assembly code that cannot work in operating systems that separate
user-mode from kernel-mode (that is, all operating systems except the Win9x
series, which is no longer supported).

This is part of cleanup for FMSLogo version 7.0, which drops support for Win9x.

Fix build breaks in the WX_PURE version.
This required copying Scintilla's private interface back
into the include directory and removing win32 API calls
for reading the joystick.

Remove assembly code that cannot work in operating systems that separate
user-mode from kernel-mode (that is, all operating systems except the Win9x
series, which is no longer supported).

This is part of cleanup for FMSLogo version 7.0, which drops support for Win9x.

Fix a build break when building screensaver with msdbg

Remove the preprocessor directives for the OWL version of FMSLogo, which no longer exists.

Remove most of the source code for Scintilla from the FMSLogo project.
Instead, it uses the Scintilla that's within the wxWidgets library.

The scintilla directory was only needed for the Borland OWL version
of FMSLogo, which has been removed.

This change is being made to prevent a casual observer from incorrectly
concluding that FMSLogo is using an old version of Scintilla and
ascribing bugs to this.