Inline TimeDiff().
Merge branch 'rulebook'
Use SDL_GetTicks() for OS::Time().
Import CXX11.cmake rev 7413d26.

https://github.com/NitroShare/CXX11-CMake-Macros
Ignore build-* directories.

These are just a common name for CMake build directories.
Add initial CMake bits.
Fix target of Doxygen comment.
Clean up init order to match declarations.
Clean up trailing whitespace.
Add TODO.
Add parens to make precedence clearer.
Remove cruft.
Fix warning ('=' used in if).
Remove unused totalSpeed.
Fix strict-aliasing warning.
Merge remote-tracking branch 'origin/master' into cmake
Define MR_ENGINE on Win32 to enable DLL exports.
Reorg and fix Win32 lib list.
Arrange sources in groups by directory.
Use static linking for LibYAML on Win32.