The bundled copies of LibPNG and zlib have been updated to the versions
shipped with FLTK (as these were convenient to build), and I've put in new
static libraries compiled with Visual Studio 2003 .NET. These libraries
link cleanly even with Visual Studio 2013 Express, so they should work for
just about every version of MSVC out there that can compile SolveSpace.
The MSVC makefile is also now a little nicer, and the SpaceWare Input
library header #includes have been adjusted to drop the si/ prefix (for
consistency with how LibPNG/zlib are handled).