Add schema.org support to EthosCE

Schema.org is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet, on web pages, in email messages, and beyond.

Many applications from Google, Microsoft, Pinterest, Yandex and others already use these vocabularies to power rich, extensible experiences.

In EthosCE the appropriate schemas would probably be Event and Course. Google will pick these up and add them to search results.

This feature has been added in EthosCE 7.30.