Move Options

This is purely a refactoring--no change in functionality and no new tests. It:

- Copies [the existing "options" documentation from the JSHint website itself](http://jshint.com/docs/options/). This makes the source code itself a little more instructive--some of the current descriptions are pretty inscrutible. I'm using code comments so users who care about filesize won't notice much difference after minification
- Corrects the location of a few existing options
- Introduces descriptions for previously-undocumented options.

There was already some duplication in terms of documentation--the terse comments in the codebase today describe many of the same options present on the website (albeit in lesser detail). In the short term, this change will create a *more* duplication, but my plan is to follow up by generating the website documentation from the code. This will make the source code itself the canonical location for options-related documentation.

Relatedly, I think any change that moves a logical component from `src/jshint.js` into a distinct module is a good thing. In this regard, a side benefit of this change is that the codebase becomes a little more approachable and a little easier to maintain