Fix pedantic compiler errors and warnings.

src/AutoPilotPlugins/APM/APMCompassCal.cc

@@ -526,6 +526,7 @@ int CalWorkerThread::sphere_fit_least_squares(const float x[], const float y[],
     //Iterate N times, ignore stop condition.
     unsigned int n = 0;
 
+#undef  FLT_EPSILON
 #define FLT_EPSILON 1.1920929e-07F  /* 1E-5 */
 
     while (n < max_iterations) {

src/MissionManager/MissionController.cc

@@ -2017,7 +2017,7 @@ void MissionController::_updateTimeout()
                 case MAV_CMD_NAV_WAYPOINT:
                 case MAV_CMD_NAV_LAND:
                 if(pSimpleItem->coordinate().isValid()) {
-                    if(pSimpleItem->command() == MAV_CMD_NAV_TAKEOFF) {
+                    if((MAV_CMD)pSimpleItem->command() == MAV_CMD_NAV_TAKEOFF) {
                         takeoffCoordinate = pSimpleItem->coordinate();
                     } else if(!firstCoordinate.isValid()) {
                         firstCoordinate = pSimpleItem->coordinate();
@@ -2025,10 +2025,10 @@ void MissionController::_updateTimeout()
                     double lat = pSimpleItem->coordinate().latitude()  + 90.0;
                     double lon = pSimpleItem->coordinate().longitude() + 180.0;
                     double alt = pSimpleItem->coordinate().altitude();
-                    north = fmax(north, lat);
-                    south = fmin(south, lat);
-                    east  = fmax(east,  lon);
-                    west  = fmin(west,  lon);
+                    north  = fmax(north, lat);
+                    south  = fmin(south, lat);
+                    east   = fmax(east,  lon);
+                    west   = fmin(west,  lon);
                     minAlt = fmin(minAlt, alt);
                     maxAlt = fmax(maxAlt, alt);
                 }

src/MissionManager/MissionItem.cc

@@ -418,7 +418,7 @@ void MissionItem::setCoordinate(const QGeoCoordinate& coordinate)
 
 QGeoCoordinate MissionItem::coordinate(void) const
 {
-    if(!isfinite(param5()) || !isfinite(param6())) {
+    if(!std::isfinite(param5()) || !std::isfinite(param6())) {
         //-- If either of these are NAN, return an invalid (QGeoCoordinate::isValid() == false) coordinate
         return QGeoCoordinate();
     }

src/QmlControls/QGCGeoBoundingCube.h

@@ -19,6 +19,7 @@ class QGCGeoBoundingCube : public QObject {
     Q_OBJECT
 public:
     QGCGeoBoundingCube(const QGCGeoBoundingCube& other)
+        : QObject()
     {
         pointNW = other.pointNW;
         pointSE = other.pointSE;