fixed times for drifting. They were still in milliseconds instead of seconds
* Changed minimum off time to 5 min
* Minimum off time for fridge constant mode is still 15 min
* Minimum time for switching  between heating and cooling is 15 min
Changed debouncing time for rotary encoder, doesn't miss detents anymore.
Prevent interrupts during LCD commands. They could cause garbage on the LCD.
INT_MAX*512 instead of INT_MAX<<9, because storage type is unknown and could lead to errors
Changed integrator windup prevention. Changed default PID parameters.
The integrator is now active when the output is not saturated (fridge temp is near fridge setting).
The old way (checking the beer slope) did not work well for slope tracking.
added new hex files. Not tested yet! Testing in progress.