addded netlink and iw based wifi scanner for linux

sensors/radio/scan/WiFiScan.h

@@ -0,0 +1,15 @@
+#ifndef INDOOR_WIFI_SCAN_H
+#define INDOOR_WIFI_SCAN_H
+
+#include "../WiFiMeasurements.h"
+
+class WiFiScan {
+
+public:
+
+	/** scan for nearby access points */
+	virtual WiFiMeasurements scan() = 0;
+
+};
+
+#endif //INDOOR_WIFI_SCAN_H