Implemented a new, better looking tooltip. (#158)

* Implemented a new, better looking tooltip.

* Pajlada fix.

* Fixed dragging behaving incorrectly.

* Fixed out of focus hovering getting stuck.

src/widgets/helper/splitheader.hpp

@@ -35,6 +35,7 @@ protected:
     virtual void paintEvent(QPaintEvent *) override;
     virtual void mousePressEvent(QMouseEvent *event) override;
     virtual void mouseMoveEvent(QMouseEvent *event) override;
+    virtual void leaveEvent(QEvent *event) override;
     virtual void mouseDoubleClickEvent(QMouseEvent *event) override;
     virtual void resizeEvent(QResizeEvent *event) override;
 
@@ -66,6 +67,9 @@ private:
 
     void initializeChannelSignals();
 
+    QString tooltip;
+    bool isLive;
+
 public slots:
     void menuMoveSplit();
     void menuReloadChannelEmotes();