DeZ80 v2.1.0

This minor release of DeZ80 modifies the InstructionDecoder API by adding push_byte() and push_slice() functions, as well as a separate try_decode() function that attempts to decode an instruction from the decoder source. decode_byte() and decode_slice() are now deprecated and will be removed in the next major release.

The new try_decode() function returns a Result<Instruction, PartialDecodeResult>, which provides some information about an instruction before there are enough bytes to decode it fully.

This release also fixes an issue with the decode_byte() function where the decoder state would be completely cleared after a successful decode even if there were more opcode bytes queued.