Modernize the C++ to accept variadic templates for signals with 6+ arguments

C++2003 didn't had variadic templates so different number of
arguments must have been already implemented in the templates
and since it's impossible to get the amount ot different methods
that paople write, a variadic template was neede.

now we can connect signal / slots with 6+ arguments.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

qgroundcontrol.pro

@@ -63,7 +63,8 @@ LinuxBuild {
 # Qt configuration
 
 CONFIG += qt \
-    thread
+    thread \
+    c++11
 
 QT += \
     concurrent \

src/FactSystem/ParameterLoader.cc

@@ -74,8 +74,7 @@ ParameterLoader::ParameterLoader(AutoPilotPlugin* autopilot, Vehicle* vehicle, Q
     _cacheTimeoutTimer.setInterval(2500);
     connect(&_cacheTimeoutTimer, &QTimer::timeout, this, &ParameterLoader::refreshAllParameters);
 
-    // FIXME: Why not direct connect?
-    connect(_vehicle->uas(), SIGNAL(parameterUpdate(int, int, QString, int, int, int, QVariant)), this, SLOT(_parameterUpdate(int, int, QString, int, int, int, QVariant)));
+    connect(_vehicle->uas(), &UASInterface::parameterUpdate, this, &ParameterLoader::_parameterUpdate);
 
     /* Initially attempt a local cache load, refresh over the link if it fails */
     _tryCacheLookup();

src/FactSystem/ParameterLoader.h

@@ -56,11 +56,9 @@ public:
     /// Returns true if the full set of facts are ready
     bool parametersAreReady(void) { return _parametersReady; }
 
-public slots:
     /// Re-request the full set of parameters from the autopilot
     void refreshAllParameters(void);
 
-public:
     /// Request a refresh on the specific parameter
     void refreshParameter(int componentId, const QString& name);
     
@@ -102,7 +100,6 @@ protected:
     Vehicle*            _vehicle;
     MAVLinkProtocol*    _mavlink;
     
-private slots:
     void _parameterUpdate(int uasId, int componentId, QString parameterName, int parameterCount, int parameterId, int mavType, QVariant value);
     void _valueUpdated(const QVariant& value);
     void _restartWaitingParamTimer(void);