guiutil.cpp/.h: fix a -Wreorder compiler warning and make constructor for ToolTipToRichTextFilter explicit

src/qt/guiutil.cpp

@@ -243,8 +243,8 @@ void openDebugLogfile()
 #endif
 }
 
-ToolTipToRichTextFilter::ToolTipToRichTextFilter(int size_threshold, QObject *parent):
-    size_threshold(size_threshold), QObject(parent)
+ToolTipToRichTextFilter::ToolTipToRichTextFilter(int size_threshold, QObject *parent) :
+    QObject(parent), size_threshold(size_threshold)
 {
 
 }

src/qt/guiutil.h

@@ -77,11 +77,11 @@ namespace GUIUtil
       representation if needed. This assures that Qt can word-wrap long tooltip messages.
       Tooltips longer than the provided size threshold (in characters) are wrapped.
      */
-    class ToolTipToRichTextFilter: public QObject
+    class ToolTipToRichTextFilter : public QObject
     {
         Q_OBJECT
     public:
-        ToolTipToRichTextFilter(int size_threshold, QObject *parent);
+        explicit ToolTipToRichTextFilter(int size_threshold, QObject *parent = 0);
 
     protected:
         bool eventFilter(QObject *obj, QEvent *evt);