Rover: rename APMrover2 to Rover

Rover/Parameters.cpp

@@ -1,7 +1,7 @@
 #include "Rover.h"
 
 /*
-  APMRover2 parameter definitions
+  Rover parameter definitions
 */
 
 #define GSCALAR(v, name, def) { rover.g.v.vtype, name, Parameters::k_param_ ## v, &rover.g.v, {def_value:def} }

Rover/Rover.cpp

@@ -14,7 +14,7 @@
 */
 
 /*
-   This is the APMrover2 firmware. It was originally derived from
+   This is the ArduRover firmware. It was originally derived from
    ArduPlane by Jean-Louis Naudin (JLN), and then rewritten after the
    AP_HAL merge by Andrew Tridgell