GitLab

I did several changes (probably I should have committed things in different steps... will do that next time)

1. Removed PENDING KEY table notes for data_models/lib/imma1_d701/imma1_d701.json. I finish all the code_tables

2. Added new data model for deck 721 data_models/lib/imma1_d721/imma1_d721.json with an encoding on the header of the file. See imma1_d721#L3

3. Fixed issue #1 (closed). Changes to the code can be seen at the end of the Changes list.