Additional PTT RIG... parameter for using DATA jack for some rigs in Hamlib

[guitarpicva]

Some rigs use special CAT or CI-V commands to PTT the "data" jack, which also routes audio through internal USB sound cards. One such radio is the IC-F8101 but there are others with internal sound cards which function similarly.

Proposal is to add another parameter to the "PTT RIG " line that directs the Hamlib library call to use it's "RIG_PTT_ON_DATA" value instead of the "RIG_PTT_ON" value. Suggest perhaps a simple keyword "DATA" or "DATA_PORT" for the config line.

[guitarpicva]

Forwarded via email the information from the Hamlib team on how to make the choice given the capabilities reply from Hamlib for the chosen radio.