Rule: no-new-require (fixes #847)

This adds the no-new-require rule and fixes #847.

> The use case for the rule - what is it trying to prevent or flag?

This rule would disallow the use of the `new require(...)` expression.

> Why you believe this rule is generic enough to be included in the main distribution

While I've only seen this manifest with r.js; it is such a subtle expression and is easily missed. Lots of people use RequireJS and could be in for a surprise when they finally decide to optimize their code (lots of people don't try it until they are about to deploy for the first time).

> Whether the rule should be on or off by default.

Since I've only seen this manifest with `r.js` and not everyone will be using `r.js`, I believe this rule should be off by default.