Add support for Google Analytics

.meteor/packages

.meteor/versions

packages/rocketchat-analytics/README.md

packages/rocketchat-analytics/client/loadScript.js

packages/rocketchat-analytics/client/trackEvents.js

packages/rocketchat-analytics/package.js

packages/rocketchat-analytics/server/settings.js

packages/rocketchat-i18n/i18n/en.i18n.json

packages/rocketchat-piwik/client/loadScript.js

packages/rocketchat-piwik/client/trackEvents.js