Merge remote-tracking branch 'upstream/master' into linux

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

Conflicts:
	src/modules/commander/accelerometer_calibration.cpp

src/modules/attitude_estimator_ekf/attitude_estimator_ekf_params.c

@@ -95,6 +95,19 @@ PARAM_DEFINE_FLOAT(EKF_ATT_V4_R1, 10000.0f);
  */
 PARAM_DEFINE_FLOAT(EKF_ATT_V4_R2, 100.0f);
 
+/**
+ * EKF attitude estimator enabled
+ *
+ * If enabled, it uses the older EKF filter.
+ * However users can enable the new quaternion
+ * based complimentary filter by setting EKF_ATT_ENABLED = 0.
+ *
+ * @min 0
+ * @max 1
+ * @group Attitude EKF estimator
+ */
+PARAM_DEFINE_INT32(EKF_ATT_ENABLED, 1);
+
 /* magnetic declination, in degrees */
 PARAM_DEFINE_FLOAT(ATT_MAG_DECL, 0.0f);