FMSLogo Code

Fix a build break when compiling against wxGTK that was introduced
by the recent switch from htmlhelp.h to using wxWidgets.

Fix bug #472; SETPIXEL now behave correctly, even in PENREVERSE mode

This was a regression that was introduced in FMSLogo 6.16.0 when I improved drawing performance by using the same screen DC and memory DC for all operating (instead of recreating them for each operation). As a result of this change, the device contexts retained their state between calls, including their ROP2 mode.

Update the instructions to reflect the latest cygwin packages. I removed gcc-g++ as a required package becuase I removed it from my machine and was still able to build FMSLogo. Perhaps it was never required. I though I had used it for windres but still have the program after removing gcc-g++, so maybe it came from both packages.

Remove the "wxWidgets" suffix from the version in the About Box. This is not unnecessary since the wxWidgets version is the only version (that is, it's implied by the version number of 7.0)

Remove the now-unused translations for LOCALIZED_ERROR_HHCTRLATOMNOTFOUND.

Remove the build-time dependency on HTML Help Workshop and instead use wxWidgets API to access the help. This became possible after the Borland OWL version was removed and the screensaver was ported to wxWidgets.

This was done to make FMSLogo easier to build.

Add a missing #include when compiling without precompiled headers

Fix problems that prevented Logolib routines from being callable on platforms
with a case-sensitive file system (Mac, GNU/Linux). I chose to normalize as
lower-case for compatibility with UCBLogo.

Fix the #include to include only the definition of wxString,
which is the only type that the macros reference.

Add comments to silent_load()