wallknob: update_win_temp function abstracting temperature window update
wallknob: update_win_humid function abstracting humidity window update
wallknob: update_win_i_charging function abstracting charging indicator window update
wallknob: update_win_i_hvac function abstracting hvac indicator window update
wallknob: weather_thread: Only update windows when they might have changed
wallknob: update_win_tempgoal function abstracting temperature goal window update
wallknob: Combine goal_thread and weather_thread
libfreeabode: fabd_{min,max} macros
wallknob: Display current frequency and goal around edge of knob