added gps support

added compass support
added ui elements for gps and compass
added support for writing sensor data

sensors/SensorFactory.h

@@ -20,6 +20,14 @@
 #include "android/BarometerSensorAndroid.h"
 #include "dummy/BarometerSensorDummy.h"
 
+#include "GPSSensor.h"
+#include "android/GPSSensorAndroid.h"
+#include "dummy/GPSSensorDummy.h"
+
+#include "CompassSensor.h"
+#include "android/CompassSensorAndroid.h"
+#include "dummy/CompassSensorDummy.h"
+
 #include "StepSensor.h"
 #include "TurnSensor.h"
 #include "ActivitySensor.h"
@@ -39,13 +47,13 @@ public:
 
 	/** set the to-be-used sensor-fatory */
 	static void set(SensorFactory* fac) {
-		Assert::isNull(*getPtr(), "set() was already called. currentely this is not intended");
+		Assert::isNull(*getPtr(), "SensorFactory::set() was already called. currentely this is not intended");
 		*getPtr() = fac;
 	}
 
 	/** get the currently configured sensory factory */
 	static SensorFactory& get() {
-		Assert::isNotNull(*getPtr(), "call set() first to set an actual factory instance!");
+		Assert::isNotNull(*getPtr(), "call SensorFactory::set() first to set an actual factory instance!");
 		return **getPtr();
 	}
 
@@ -63,6 +71,13 @@ public:
 	/** get the Barometer sensor */
 	virtual BarometerSensor& getBarometer() = 0;
 
+	/** get the compass sensor */
+	virtual CompassSensor& getCompass() = 0;
+
+	/** get the gps sensor */
+	virtual GPSSensor& getGPS() = 0;
+
+
 	/** get the Step sensor */
 	StepSensor& getSteps() {
 		static StepSensor steps(getAccelerometer());