Fix whisper receiving

Added setting to display them inline under "Special Channels" page

Store a twitch users color in the TwitchUser struct
this is useful if we ever want to use the users own color.
The users own color is only updated once he has written once in chat

Add helper method for calling function only on normal channels

Fixes #54

src/singletons/channelmanager.cpp

@@ -138,5 +138,12 @@ void ChannelManager::doOnAll(std::function<void(ChannelPtr)> func)
     func(this->mentionsChannel);
 }
 
+void ChannelManager::doOnAllNormalChannels(std::function<void(ChannelPtr)> func)
+{
+    for (const auto &channel : this->twitchChannels) {
+        func(std::get<0>(channel));
+    }
+}
+
 }  // namespace chatterino
 }