textarea width

We can safely increase the textarea width from 98% to 100%. 

```box-sizing``` handles the layout nicely and it won't allow the overflow. 

If more details is needed, please see: http://davidwalsh.name/textarea-width this is the best example I could find.
Merge pull request #501 from emiluzelac/patch-23

Increases text width to 100% which allows for box-sizing. I like this better and if someone wants to add a border or effect they can change the width.
Post Formats code re-formatting

See: https://github.com/Automattic/_s/pull/498#issuecomment-44492997
Merge pull request #502 from emiluzelac/patch-24

Minor coding standards adjustments for HTML5 markup support declaration. See https://github.com/Automattic/_s/pull/498#issuecomment-44492997.