Add several discouraged JavaScript features

[ddbeck]

This PR adds several discouraged JavaScript features, building on @captainbrosset's work in #2564. The features are:

• Accessor methods (__defineGetter__() and __defineSetter__())
• Date.prototype.{get,set}Year()
• Date.prototype.toGMTString()
• escape() and unescape() global methods
• HTML wrapper methods (e.g., String.prototype.blink())
• Object.prototype.__proto__
• RegExp.prototype.compile()

Supersedes and closes #2564.

[captainbrosset]

Just a few comments.