BLE HF2 log service (#1549)

* basic hf2 service

* service to send hf2 log messages

* use common console.log

* updated shims

* adding config

* adding simulator

* fix hf2 logging

* hide console blocks

libs/core/control.cpp

@@ -311,4 +311,13 @@ namespace control {
     void __midiSend(Buffer buffer) {
         // this is a stub to support the simulator
     }
+
+    /**
+    *
+    */
+    //%
+    void __log(String text) {
+        if (NULL == text) return;
+        pxt::sendSerial(text->data, text->length);
+    }
 }