Calibrate compass (#392)

* adding 'calibrate-compass' function

* fixing simulator.

* updated docs

* fixing compat test suite with 'calibrate()' function

sim/state/misc.ts

@@ -78,7 +78,8 @@ namespace pxsim.input {
         return runtime.runningTime();
     }
 
-    export function calibrate() {
+    export function calibrateCompass() {
+        // device calibrates...
     }
 }