Update xz-utils to 5.0.5 and add build script for it.
Convert all usage of throw to noexcept (fix Clang deprecated warnings).
Update libav to 9.10.
Remove unused constants and functions from script engine.
Use RX_INLINE throughout the code.
Forward declare a few classes in RXGameState.h instead of importing their headers.
Bump the project upgrade check to Xcode 5.1.
Replace the clowny random number functions with more sound functions based on <random>.