Added note to WeakMap and WeakSet results

WeakMap and WeakSet constructor arguments, such as new WeakSet([obj1,
obj2]), are not supported in most browser platforms.
Added a further note to Map and Set results

Additionally, it seems only Firefox supports arguments to the Map() and
Set() constructors.
Merge pull request #208 from webbedspace/weakmapnote

Added note to WeakMap and WeakSet results
FF34 now supports shorthand methods
ES6: Added tests for each Proxy handler

This adds tests for the Proxy get, set, has, deleteProperty,
getOwnPropertyDescriptor, defineProperty, getPrototypeOf,
setPrototypeOf, isExtensible, preventExtensions, enumerate, ownKeys,
apply and construct handlers.
EJS support is inferred from the source.

Also fixes a few other results for old Firefox versions.

Sorry that this diff looks terrible, but if you run `git diff
--minimal`, it more accurately reflects the changes.
Added missing property names to the Reflect test
Added a Proxy.revocable test