fiddle with flags a bit

MavJS didn't like how CMake ignored the environment's flags and always used the project's flags; so he made it so CMake always ignored the project's. Either way, it seems the same thing happens: CMake's flags are appended to the environment's flags; "-O3" seems to be CMake's default if the project's aren't used. Both of these options suck (thanks CMake), so… will have to figure something out. For now, I'm for reverting it to how it was.