Rewrite pid_control.c for variable PID settings
httpd.c: Rewrite for control of PID values
Adjust root template for control of PID values
pid_control.c: Fix reference
httpd.c: Changed some #ifs connected to the PID control settings
Initialize PID
note about musl printf in README
httpd.c: Add templating thing to handle >= 10 variables in templates
Remove musl note in README
Merge branch 'feature/http-pid-control' into develop
Merge branch 'develop' of github.com:Cat-Ion/raspberrypi-incubator into develop