JSON output for generate_successor_table.py

[clemos]

I've ported shoco to Haxe (and thus all its targets, incl JS): https://github.com/clemos/shocohx
Now I would like to add a JSON output to generate_successor_table.py, because I can't work directly with the .h files that the script outputs currently.
I thought about simply adding a new --output-format {json,headerfile} flag.
Would you welcome a PR with this feature, or do you think it would make more sense to just add it to my repo ?
In any case, thanks a lot for your work :D

[clemos]

FYI it's currently here :
https://github.com/clemos/shocohx/blob/master/generate_compressor_model.py