Merge pull request #2198 from RocketChat/fix-message-notifications

packages/rocketchat-lib/package.js

packages/rocketchat-lib/server/functions/sendMessage.coffee

packages/rocketchat-lib/server/lib/notifyUsersOnMessage.js

packages/rocketchat-lib/server/lib/sendEmailOnMessage.js

...s/rocketchat-lib/server/lib/sendNotificationsOnMessage.js

packages/rocketchat-lib/server/models/Rooms.coffee

packages/rocketchat-lib/server/models/Users.coffee

packages/rocketchat-mentions/server.coffee

packages/rocketchat-ui/lib/notification.coffee