FMSLogo Code

Drop support for paletted display devices. After dropping suppport for Windows 95/98/ME, the logic for populating and clearing the system palette became unneeded as there are no longer any display devices which use a color palette. By removing the logic to support this now-defunct technology, the FMSLogo code base is made simpler and easier to port to a non-Windows platform using pure wxWidgets API.

Rework the #ifndef WX_PURE so that paste_all_turtles() is called
when compiling for non-Windows platforms (which was the entire
purpose of the previous change to make it take a wxDC, instead
of an HDC). So now the turtle appears on GNU/Linux.

Change paste_all_turtles so that it uses a wxDC instead of a HDC, which is only available on Windows. This was done to make the turtle appear on the experimental version of FMSLogo that runs on GNU/Linux.

Fix a problem introduced in the previous revision where the mkdir didn't get called (I had thought that "?" was the character that disables echo, but it's "@", and after using it, I released that it's not what I want either, as it doesn't mute the response).

Fix a build break when using precompiled headers and building for
non-Windows platforms.

Fix a problem with the Makefile where modifying a header did not
cause the precompiled header (which includes all of them) to be
rebuilt.

Add support for precompiled headers in the build for the main FMSLogo environment (not the screensaver). On my machine, this reduced the build time of each executable from ~3m 30s to ~1m 30s.

Fix the link to the changelog (the URL was based on the CVS repository, which has been replaced with a Subversion repository).

Fix a bug in the WM_ERASEBKGND message handler of the screensaver that caused it to erase the entire screen, instead of the region that needed erasing. My fix is redundant, in that merely using the HDC that was passed in as the WPARAM appeared to be sufficient (as the HDC presumably is clipping the parts that don't need updated). However to be sure, the screensaver only erases the rectangle that is invalid.

While this bug has existed since the initial release of the FMSLogo screensaver, it only became noticable now, as I recently implemented the windowing command set in the screensaver, which makes it possible to show/hide windows on top of the screensaver. When a window is hidden, the WM_ERASEBACKGROUND message is sent to repaint the region where the window was. Due to the bug, the entire screen would be made white, then only the region under the window would be repainted with WM_PAINT.

Fix a syntax error in WXSTRING_TO_STRING when compiled with wxUSE_UNICODE.