If content pages are fully rendered in a list page, footnotes that use
the same reference (`[^fn]`) will have duplicated anchors. This change
builds on #526 to put the page filename (`Page.File.Name`) as part of
the anchor for a footnote.
This would fix discussion [116](http://discuss.gohugo.io/t/footnote-references-are-duplicated-on-list-pages/116).
It started with wanting to move templates in template bundles and the
rest followed. I did my best to start grouping related functions
together, but there are some that I missed. There is also the method
Urlize that seems to be a special function used in both worlds. I'll
need to revisit this method.
