Support arbitrary-length integers in Integer instruction.
Suport arbitrary-length natural numbers in the Natural instruction.
Simplify tests for ByteSequence.make_bytecode and ByteSequence.read_bytecode.
Add ByteStream and ArrayStream. Change BytecodeProcessor to ByteStreamProcessor, so it uses a ByteStream object instead of a simple byte array. CHange instruction classes to make values from a bytestream instead of a simple byte array.
A bit of reorganizing.
Add Rational instruction class.