Huge refactor

- Remove some underscore-prefixes
 - Start using this-> more
 - Remove a few of the singletons (We pass references to managers to
         things that need it now. Might not be much better, but for now
         it works. It also shows what places might be slightly wrong
         designed)

src/channelmanager.hpp

@@ -4,13 +4,15 @@
 
 namespace chatterino {
 
+class WindowManager;
+class EmoteManager;
+class IrcManager;
+
 class ChannelManager
 {
 public:
-    static ChannelManager &getInstance()
-    {
-        return instance;
-    }
+    explicit ChannelManager(WindowManager &_windowManager, EmoteManager &_emoteManager,
+                            IrcManager &_ircManager);
 
     std::shared_ptr<Channel> getWhispers();
     std::shared_ptr<Channel> getMentions();
@@ -23,9 +25,9 @@ public:
     void removeChannel(const QString &channel);
 
 private:
-    static ChannelManager instance;
-
-    ChannelManager();
+    WindowManager &windowManager;
+    EmoteManager &emoteManager;
+    IrcManager &ircManager;
 
     QMap<QString, std::tuple<std::shared_ptr<Channel>, int>> _channels;
     QMutex _channelsMutex;