Convert ipuz Crosswords to puz format.

This relies on the puzpy and ipuz libraries. To install dependencies: pip install -r requirements.txt.

xfer.py takes two parameters: an ipuz input file and a puz output file. dump.py dumps a puz-formatted file for easy viewing.

Inside xfer.py is a boolean flag called output that defaults to True, which means print in the puz binary format. If you want to print in the puz text format, change output to False and store it in a text file. AcrossLite will be able to read the ASCII file and convert it to binary, if you wish.

Other links:

• Documentation on the ipuz format
• Documentation on the text puz format There is no meaningful documentation on the puz binary file format.

Finally, this only supports very basic format. It doesn't supportipuz-type rebus and special objects in shapes.

I'd be willing to consider tests before adding more powerful features.