PID: Add a full reset method

libraries/PID/PID.cpp

@@ -119,6 +119,11 @@ PID::reset_I()
     _pid_info.I = 0;
 }
 
+void PID::reset() {
+    memset(&_pid_info, 0, sizeof(_pid_info));
+    reset_I();
+}
+
 void
 PID::load_gains()
 {

libraries/PID/PID.h

@@ -39,6 +39,10 @@ public:
     ///
     float        get_pid(float error, float scaler = 1.0);
 
+    /// Reset the whole PID state
+    //
+    void        reset();
+
     /// Reset the PID integrator
     ///
     void        reset_I();