Modified the way that story metadata tags are added to headers.

The character set specification should be the very first thing within the header, next should be the `<title>` tag, only then should additional `<meta>` tags be specified (the first of which should probably be "description" if you're worried about search engines parsing it).

With that in mind, I:
- Moved `<title>…</title>` to just after character set specification in the vanilla headers.
- Modified the insertion code to add story metadata tags after the closing `</title>` tag.