FMSLogo Code

Add a few more backward-compatibility tests for DLLCALL.
(strtod and atoi only check the prefix)

Update the patch for imagbmp.cpp to be what I submitted to the wxWidgets master.
This doesn't use exceptions but instead tests that biClrUsed is in a reasonable range.

Cleanup: Remove some unused variables

Reduce the size of the back buffer that is used to remove flicker when using rotating bitmapped turtles.
Instead of being the size of the drawing surface, it's now just enough of the drawing surface needed to be able to draw the screen.

Refactoring
- Extract a function for commonality between SetWrappedPixel/GetWrappedPixel
- Add min4/max4, which is clearer than nested min/max calls.
- Improve comments

Fix Bug #578; OPENWRITE, OPENREAD, OPENAPPEND, and OPENUPDATE can now open files with names that have special characters quoted by vertical bars.
The problem was that the remapping of the special characters that marked them as vbarred wasn't undone before passing the filename to fopen().

Update BITLOAD.MALFORMED to match the behavior of wxImage

Add a commented out directive to use a large address space.
This, along with a boot configuration change, enables a 32-bit program to use 3GB of memory on a 64-bit host OS.
There is some compatibility risk, so it's disabled until I can test it well.

Use the calculated realsize in debug_malloc instead of calculating it twice.

Fix a regression introduced when using wxImage to load bitmaps.
If the biClrUsed was negative or large, wxImage::LoadFromFile would throw a bad_alloc exception, causing FMSLogo to crash.
This is now patched in the library and (in case an unpatched library is used) also handled in FMSLogo.