Track down blank lines in output documents

[lyzadanger]

Prettier is going to insist on putting a blank line between the end of front-matter and the first tag in the template. This results in leading blank lines in output. I've "fixed" this in the outermost set of templates and layouts — ensuring that HTML documents and RSS documents do not lead with blank lines — but there are still some output documents that have excessive numbers of blank lines. Track this down.