nexus: Implement wifi scanner and fix a lot of bugs

Signed-off-by: San Mehat <san@google.com>
diff --git a/nexus/TiwlanWifiController.h b/nexus/TiwlanWifiController.h
index a93d610..f17ef51 100644
--- a/nexus/TiwlanWifiController.h
+++ b/nexus/TiwlanWifiController.h
@@ -27,5 +27,6 @@
     virtual int powerDown();
     virtual bool isPoweredUp();
     virtual int loadFirmware();
+    virtual bool isFirmwareLoaded();
 };
 #endif