[chirp_devel] [PATCH 0 of 2] Initial RadioReference.com import support

Here is my initial attempt at RadioReference.com import support. It adds a menu for RadioReference.com import which prompts for a zipcode. It determines the county for that zipcode and downloads all frequencies in the RR database for that county. There is no means to request state or federal frequencies with this UI.

This feature requires a RadioReference.com Premium Subscription.

If there is interest, I'll improve the UI so data can be queried with other parameters (zipcode is very limiting).

Tom KD7LXL