Merge remote-tracking branch 'upstream/master' into start-poll-01

bigbluebutton-html5/client/main.html

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

...l5/imports/api/meetings/server/modifiers/removeMeeting.js

...esentation-pods/server/modifiers/clearPresentationPods.js

...esentation-pods/server/modifiers/removePresentationPod.js

...ad-token/server/modifiers/clearPresentationUploadToken.js

.../api/presentations/server/modifiers/clearPresentations.js

bigbluebutton-html5/imports/api/slides/server/methods.js

...tton-html5/imports/api/slides/server/methods/zoomSlide.js

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

bigbluebutton-html5/imports/ui/components/chat/styles.scss

...on-html5/imports/ui/components/presentation/component.jsx

...omponents/presentation/presentation-overlay/component.jsx

...omponents/presentation/presentation-overlay/container.jsx

...omponents/presentation/presentation-toolbar/component.jsx

...omponents/presentation/presentation-toolbar/container.jsx

...i/components/presentation/presentation-toolbar/service.js

.../components/presentation/presentation-toolbar/styles.scss

...presentation/presentation-toolbar/zoom-tool/component.jsx

...d/whiteboard-overlay/pan-zoom-draw-listener/component.jsx