Integrate known 'renderMethod' property and classes into the VC DM 2.1 context

[dmitrizagidulin]

Several interrelated topics.

1. Ensure renderMethod compatibility with VC DM 1.1 and 2.0

• Easiest thing to do would be to publish a standalone @context file for VC DM 1.1 that includes the renderMethod property itself, as well as the known classes and their properties, for use with 1.1
• Note: renderMethod property and its class is in the VC DM 2.0 base context, but defining it in

2. Include the render method property and known classes in the future VC DM 2.1

3. Add any missing terms to the vocabulary

See also:

• related issue publish context file for renderMethod #16