Langauge selection options in language they represent

[henrygab]

• Translation selection should be in language it represents

json2h.py

• Prevent accidental translation of language selection text using regex (to avoid constant need to update this script).
• Explicitly require Python 3.7 or higher
• Warn about non-compliant identifiers
• Tabs to spaces in generated .h files
• Use functions to logically separate code portions
• Provide progress output
• output fixed-width key (also helps highlight overlong identifiers)

*.json

• Remove unused key/value pairs. Generated .h files were unchanged, confirming non-use