add flag to enable monitoring, correct who can see network problems and update logic

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

...5/imports/api/users/server/methods/userChangedSettings.js

.../imports/api/users/server/modifiers/setChangedSettings.js

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

...ml5/imports/ui/components/notifications-bar/container.jsx

...r-participants/user-list-item/user-dropdown/component.jsx

...user-participants/user-list-item/user-icons/component.jsx

...on-html5/imports/ui/services/network-information/index.js

bigbluebutton-html5/imports/ui/services/settings/index.js

bigbluebutton-html5/private/config/settings.yml