Fix GUI compilation error with unnamed namespace at some compilers.

CMakeLists.txt

@@ -9,7 +9,7 @@ project(BornAgain)
 # --- The version number ---
 set(BornAgain_VERSION_MAJOR 1)
 set(BornAgain_VERSION_MINOR 0)
-set(BornAgain_VERSION_PATCH 0)
+set(BornAgain_VERSION_PATCH 1)
 
 # --- General project settings ---
 option(BORNAGAIN_PYTHON "Build with python support" ON)

GUI/externals/qt-manhattan-style/extensions/threelevelsitempicker.cpp

@@ -168,7 +168,7 @@ QString ThreeLevelsItemPicker::level3() const
     return item ? item->text() : QString();
 }
 
-namespace
+namespace helper_namespace
 {
 
 QListWidgetItem* find(const ListWidget* list, const QString& name)
@@ -187,21 +187,21 @@ QListWidgetItem* find(const ListWidget* list, const QString& name)
 
 void ThreeLevelsItemPicker::setLevel1Item(const QString& name)
 {
-    QListWidgetItem* item = ::find(m_level1Items, name);
+    QListWidgetItem* item = helper_namespace::find(m_level1Items, name);
     if (item)
         m_level1Items->setCurrentItem(item);
 }
 
 void ThreeLevelsItemPicker::setLevel2Item(const QString& name)
 {
-    QListWidgetItem* item = ::find(m_level2Items, name);
+    QListWidgetItem* item = helper_namespace::find(m_level2Items, name);
     if (item)
         m_level2Items->setCurrentItem(item);
 }
 
 void ThreeLevelsItemPicker::setLevel3Item(const QString& name)
 {
-    QListWidgetItem* item = ::find(m_level3Items, name);
+    QListWidgetItem* item = helper_namespace::find(m_level3Items, name);
     if (item)
         m_level3Items->setCurrentItem(item);
 }