added kernel density wrapper

added general kld solution
fixed minor bugs
added tests

sensors/offline/FileReader.h

@@ -193,7 +193,7 @@ namespace Offline {
 			WiFiMeasurements wifi;
 			Splitter s(data, sep);
 
-			for (size_t i = 0; i < s.size(); i += 3) {
+            for (size_t i = 0; i < s.size()-1; i += 3) {
 
 				const std::string mac = s.get(i+0);
 				const float freq = s.getFloat(i+1);