Moved online status checking logic from ChatWidgetHeader to TwitchChannel

- Channel now needs to be initialized with a name. Special cases like the emote window just sends an empty string.
 - ChatWidget now has a signal which is called whenever the widgets channel is changed
 - Changed roomID from an std::string to a QString

src/widgets/chatwidgetheader.hpp

@@ -12,6 +12,7 @@
 #include <QPaintEvent>
 #include <QPoint>
 #include <QWidget>
+#include <boost/signals2/connection.hpp>
 
 namespace chatterino {
 
@@ -29,7 +30,6 @@ public:
     explicit ChatWidgetHeader(ChatWidget *_chatWidget);
     // Update channel text from chat widget
     void updateChannelText();
-    void checkLive();
 
 protected:
     virtual void paintEvent(QPaintEvent *) override;
@@ -44,6 +44,8 @@ private:
     QPoint dragStart;
     bool dragging = false;
 
+    boost::signals2::connection onlineStatusChangedConnection;
+
     QHBoxLayout hbox;
 
     // top left
@@ -62,6 +64,8 @@ private:
 
     virtual void refreshTheme() override;
 
+    void initializeChannelSignals();
+
 public slots:
     void menuMoveSplit();
     void menuReloadChannelEmotes();