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/window.hpp

@@ -11,6 +11,7 @@
 
 #include <boost/signals2.hpp>
 #include <pajlada/settings/setting.hpp>
+#include <pajlada/signals/signal.hpp>
 
 namespace chatterino {
 
@@ -55,9 +56,13 @@ public:
 
     boost::signals2::signal<void()> closed;
 
+    pajlada::Signals::NoArgSignal lostFocus;
+
 protected:
     virtual void closeEvent(QCloseEvent *event) override;
 
+    virtual void changeEvent(QEvent *event) override;
+    virtual void leaveEvent(QEvent *event) override;
 private:
     float dpi;