Hamlib version 3.0

Two days ago (after 3 years of silence) Hamlib developers released version 3.0 of the library!

According to README, there are a couple of drops and new additions of hardware support. I am not entirely sure if that affects us (or enables us!) for the current implementation we have.

Thoughts? (cc @johngian, @Acinonyx, @planetsofa, @cshields, @azisi )

They took my proposed new easycomm2/3 protocols, which I intended to extend talkback features from a rotator (to get some parameters back from the rotator for closed loop) into the main branch in rotctld. Otherwise I notice nothing.