Method hash

test/IECore/ComputationCacheTest.cpp:58–64

	typedef ComputationCache< ComputationParams > Cache;

	static MurmurHash hash( const ComputationParams &params )
	{
		int id = params;
		MurmurHash h;
		h.append(id);
		return h;
	}

	static IntDataPtr get( const ComputationParams &params )
	{