Added tests for Proxy handlers and Proxy.revocable

This is a re-working of a previous branch. This adds tests for the Proxy get, set, has, deleteProperty, getOwnPropertyDescriptor, defineProperty, getPrototypeOf, setPrototypeOf, isExtensible, preventExtensions, enumerate, ownKeys, apply and construct handlers, as well as Proxy.revocable. EJS support is inferred from the source.