Other Posts in Series fix.

main.min.css was a couple of huge lines. Made it pretty so its easy to
modify, also added new IDs for disqus_comments CSS so the same style can
be used without invoking Disqus javascript. The style is now also used
by the Other Posts in Series <section />.

index.html and Other Posts in Series now share the use the same logic,
so it's organized better. The published/updated date is also included in
both pages.

Moved Other Posts in Series below main post and above comments. This
fixed the ugly spacing issue, and I think it should go down there
anyways.

Related Posts now mentioned updated date if the page has been updated.