Add a simple BinaryCoder class which is like Lilliput.ByteBuffer, but backed by NSMutableData

- so far all tests pass.
Split BinaryCoder into two

BinaryCoder is immutable, and lightweight wrapper around an NSData instance.
MutableBinaryCoder is a mutable subclass
Update IO pipeline to use BinaryCoder & MutableBinaryCoder

- updated tests to match
Removed submodule Lilliput
Add ByteOrder from Lilliput to BinaryCoding