Improve "Incompatible locale" check.

This flaw is fixed in C++17.

src/app/puzzle/vpapplication.cpp

@@ -402,14 +402,14 @@ void VPApplication::InitOptions()
     qCDebug(pApp, "Command-line arguments: %s", qUtf8Printable(arguments().join(QStringLiteral(", "))));
     qCDebug(pApp, "Process ID: %s", qUtf8Printable(QString().setNum(applicationPid())));
 
-    CheckSystemLocale();
-
     QPixmapCache::setCacheLimit(50 * 1024 /* 50 MB */);
 
     LoadTranslation(QString());// By default the console version uses system locale
 
     VPCommandLine::Instance();
 
+    CheckSystemLocale();
+
     static const char * GENERIC_ICON_TO_CHECK = "document-open";
     if (not QIcon::hasThemeIcon(GENERIC_ICON_TO_CHECK))
     {

src/app/tape/mapplication.cpp

@@ -441,10 +441,10 @@ void MApplication::InitOptions()
     qCDebug(mApp, "Command-line arguments: %s", qUtf8Printable(arguments().join(QStringLiteral(", "))));
     qCDebug(mApp, "Process ID: %s", qUtf8Printable(QString().setNum(applicationPid())));
 
-    CheckSystemLocale();
-
     LoadTranslation(QString());// By default the console version uses system locale
 
+    CheckSystemLocale();
+
     static const char * GENERIC_ICON_TO_CHECK = "document-open";
     if (not QIcon::hasThemeIcon(GENERIC_ICON_TO_CHECK))
     {

src/app/valentina/core/vapplication.cpp

@@ -613,13 +613,13 @@ void VApplication::InitOptions()
     qDebug()<<"Command-line arguments:"<<arguments();
     qDebug()<<"Process ID:"<<applicationPid();
 
-    CheckSystemLocale();
-
     LoadTranslation(QString());// By default the console version uses system locale
 
     // Create command line parser after loading translations to show localized version.
     VCommandLine::Get(*this);
 
+    CheckSystemLocale();
+
     if (VApplication::IsGUIMode())// By default console version uses system locale
     {
         LoadTranslation(ValentinaSettings()->GetLocale());

src/libs/vgeometry/vabstractcurve.cpp

@@ -40,6 +40,12 @@
 #include "../vmisc/compatibility.h"
 #include "../ifc/exception/vexceptionobjecterror.h"
 
+// See https://stackoverflow.com/a/46719572/3045403
+#if __cplusplus < 201703L
+constexpr qreal VAbstractCurve::minLength; // NOLINT(readability-redundant-declaration)
+#endif
+
+//---------------------------------------------------------------------------------------------------------------------
 VAbstractCurve::VAbstractCurve(const GOType &type, const quint32 &idObject, const Draw &mode)
     :VGObject(type, idObject, mode), d (new VAbstractCurveData())
 {}