Merge remote-tracking branch 'upstream/develop' into develop

.../src/main/scala/org/bigbluebutton/core/models/Polls.scala

.../main/java/org/bigbluebutton/api/ParamsProcessorUtil.java

...g/bigbluebutton/presentation/imp/ThumbnailCreatorImp.java

bigbluebutton-config/bigbluebutton-release

bigbluebutton-config/bin/bbb-conf

bigbluebutton-html5/client/main.html

bigbluebutton-html5/imports/api/annotations/addAnnotation.js

...uebutton-html5/imports/api/audio/client/bridge/kurento.js

.../api/group-chat-msg/server/modifiers/clearGroupChatMsg.js

...html5/imports/api/meetings/server/modifiers/addMeeting.js

...orts/api/users-settings/server/methods/addUserSettings.js

...ton-html5/imports/api/users-settings/server/publishers.js

...utton-html5/imports/api/users/server/modifiers/addUser.js

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

.../ui/components/actions-bar/actions-dropdown/component.jsx

...ts/ui/components/breakout-join-confirmation/component.jsx

...tton-html5/imports/ui/components/captions/pad/styles.scss

...l5/imports/ui/components/chat/chat-dropdown/component.jsx

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

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