The VS 6 version of wincrypt.h only works if _WIN32_WINNT >= 0x0400.
We block its inclusion through windows.h by defining NOCRYPT, and then
define _WIN32_WINNT and include it only when necessary.
This allows for a built in bzip and zip capability, so external tools
will not be needed for these packagers. The cmake -E tar xf should be
able to handle all compression types now as well.
Brad King
Bill Hoffman