Fixed a few bugs related to initializing and interrupt handling of buttons.
Made the activation of the alarm and LED displays more consistent (for both serial commands and the physical interface).
Implemented a setpoint button which, when pressed, shows the current setpoint in the 7-segment display. The encoder can now only change the setpoint when this button is pressed.
Fixed the missing reset of the PID controller integral on activation of the controller via button.
Added the initialization of the heating/cooling signal pin and function macros to turn this signal on and off.