New: space-in-parens rule

Closes #627.

You'll notice that I set the rule to off by default. This is to be consistent with the existing `space-in-brackets` rule which seems closely related as more of a stylistic concern. I can easily switch it back to on by default as @nzakas originally said; however that will also require either setting it to off in eslint's .eslintrc or correcting the 20 or so files that currently fail it.
Also put in a copyright for yourself. I'm trying to do this with all files from now on to help with acceptance by strict open source projects wanting to use ESLint. It looks like this:

```
/**
 * (Desc)
 * @author Jonathan Rajavuori
 * @copyright 2014 Jonathan Rajavuori. All rights reserved.
 */
```