begin cleanup on gps code

src/GPS.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <TinyGPS++.h>
+#include "PeriodicTask.h"
+#include "Observer.h"
+
+/**
+ * A gps class that only reads from the GPS periodically (and FIXME - eventually keeps the gps powered down except when reading)
+ * 
+ * When new data is available it will notify observers.
+ */
+class GPS : public PeriodicTask, public Observable, public TinyGPSPlus
+{
+public:
+    GPS();
+
+    String getTime();
+
+    void setup();
+
+    virtual void loop();
+
+    virtual void doTask();
+};
+
+extern GPS gps;