fix unread messages counter on public chat and remove some old chat configurations

bigbluebutton-html5/imports/api/group-chat-msg/index.js

...rts/api/group-chat-msg/server/methods/sendGroupChatMsg.js

...ton-html5/imports/api/group-chat-msg/server/publishers.js

.../imports/api/group-chat/server/methods/createGroupChat.js

...ebutton-html5/imports/api/group-chat/server/publishers.js

bigbluebutton-html5/imports/startup/client/base.jsx

bigbluebutton-html5/imports/ui/components/chat/container.jsx

...ml5/imports/ui/components/chat/notification/component.jsx

...ml5/imports/ui/components/chat/notification/container.jsx

bigbluebutton-html5/imports/ui/components/chat/service.js

...uebutton-html5/imports/ui/components/user-list/service.js

...er-list/user-list-content/user-participants/component.jsx

...button-html5/imports/ui/services/unread-messages/index.js

bigbluebutton-html5/private/config/settings-development.json

bigbluebutton-html5/private/config/settings-production.json

bigbluebutton-html5/server/main.js