Get Incursion Visual Studio solution/projects building on x64 platform

[RMTEW FULL NAME]

This should be a simple matter of:

1. Adding a new platform configuration to the solution.
2. Adding property sheets if necessary for the different platforms.
3. Test the compilation and make sure there's no deal breakers in the source code.
4. If all goes well, upgrade the build script to do it automatically, and do everything up to and including building releases.

[RMTEW FULL NAME]

Close #248. Incursion now 'compiles' on x64. Note that modaccent does not as it does not like x64 and crashes, but you can always run the Win32 version, so it's not a deal breaker. x64 compilation has lots of warnings, so may not be ready for play.

→ <<cset 2c1ce107c2d1>>