Add collection user persistent data

.../imports/api/meetings/server/modifiers/meetingHasEnded.js

...uebutton-html5/imports/api/users-persistent-data/index.js

...n-html5/imports/api/users-persistent-data/server/index.js

...persistent-data/server/modifiers/addUserPersistentData.js

...sistent-data/server/modifiers/clearUsersPersistentData.js

...users-persistent-data/server/modifiers/setOnlineStatus.js

...l5/imports/api/users-persistent-data/server/publishers.js

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

...on-html5/imports/api/users/server/modifiers/removeUser.js

bigbluebutton-html5/server/main.js