Merge pull request #3435 from JaeeunCho/messages_v1

...ml5/imports/ui/components/chat/message-form/component.jsx

...ponents/chat/message-list/message-list-item/component.jsx

...omponents/chat/message-list/message-list-item/styles.scss

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

...tml5/imports/ui/components/user-avatar/color-generator.js

...ton-html5/imports/ui/components/user-avatar/component.jsx

...utton-html5/imports/ui/components/user-avatar/styles.scss

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