dro_split -d throws exception on DRO v1 files

[jestar jokin]

Exception:

Traceback (most recent call last):
  File "E:\Apps\Programming\Python27\lib\threading.py", line 551, in __bootstrap_inner
    self.run()
  File "D:\temp\hg\DROTrimmer_v3\src\dro_player.py", line 45, in inner_func
    func(self, *args, **kwds)
  File "D:\temp\hg\DROTrimmer_v3\src\dro_player.py", line 502, in run
    self.dro_player.processing_streams.write(inst.command, inst.value)
  File "D:\temp\hg\DROTrimmer_v3\src\dro_player.py", line 113, in write
    stream.write(register, value)
  File "D:\temp\hg\DROTrimmer_v3\src\dro_capture.py", line 55, in write
    code = self.code_map[register] | (self.bank << 7)
KeyError: 17

This can occur when splitting DRO v1 files, but actually seems to be caused by writing to "unknown" registers, so could theoretically affect DRO v2 files.

[jestar jokin]

Fixed in v4 r4.