Added etag, cache-control, last-modified, date, and charset headers
v6.60.0. Improvement.

- v6.60.0 January 16, 2014
	- Added `etag`, `cache-control`, `last-modified`, `date`, and
`charset` headers
		- Thanks to [Marcus Stong](https://github.com/stongo) for [issue
#740](https://github.com/bevry/docpad/issues/740)
Added david badges