Implement an advanced method of adding a user to chatterino.

You can now switch between multiple users in the settings dialog.
(Requires a restart for reconnecting etc)

src/accountmanager.cpp

@@ -67,9 +67,24 @@ twitch::TwitchUser &AccountManager::getTwitchUser()
         return this->getTwitchAnon();
     }
 
+    std::string currentUser = pajlada::Settings::Setting<std::string>::get("/accounts/current");
+
+    QString currentUsername = QString::fromStdString(currentUser);
+
+    for (auto &user : this->twitchUsers) {
+        if (user.getUserName() == currentUsername) {
+            return user;
+        }
+    }
+
     return this->twitchUsers.front();
 }
 
+void AccountManager::setCurrentTwitchUser(const QString &username)
+{
+    pajlada::Settings::Setting<std::string>::set("/accounts/current", username.toStdString());
+}
+
 std::vector<twitch::TwitchUser> AccountManager::getTwitchUsers()
 {
     std::lock_guard<std::mutex> lock(this->twitchUsersMutex);