Add README.freqranges to explain what's going on with this feature
Add default ITU definitions to bandplan.h
The ITU definitions will likely change as the backends are updated dependinggg on the rig models
https://github.com/Hamlib/Hamlib/issues/243
Power levels and ranges need to be verified
Plus is there more than one FT847 model...e.g. a U.K. version?
I see FT847 mods to open up 4M so this may just be a customization.
https://github.com/Hamlib/Hamlib/issues/243