begin cleanup on gps code

src/Observer.cpp

@@ -0,0 +1,13 @@
+#include "Observer.h"
+
+Observer::~Observer()
+{
+    if (observed)
+        observed->removeObserver(this);
+    observed = NULL;
+}
+
+void Observer::observe(Observable *o)
+{
+    o->addObserver(this);
+}