Option to use filename as replacement

Parse a filename structure like this: `2014-02-11-foo.{hbs,md}` and convert it to something like this: `dest/blog/2014/02/11/foo/index.html` (or depends on [`preset`](https://github.com/assemble/assemble-contrib-permalinks#preset))

**Update**

I'll attach commit to add filename replacement option with two test using `preset` and `structure`.

When this option `true`, the date will be stripped from filename and then modify `page.basename`
and `page.slug` to use replacement version.

And then date strip from filename added to `page.data.date` property if it not exist in yfm data.