move past-events and resources pages to subdirs

fix for belfastruby/belfastruby.com#18
use pre-compile logic for active nav items instead of JS
only show past events on the past events page
Merge branch 'serve-without-html-extension' of https://github.com/cobyism/belfastruby.com into cobyism-serve-without-html-extension

* 'serve-without-html-extension' of https://github.com/cobyism/belfastruby.com:
  only show past events on the past events page
  use pre-compile logic for active nav items instead of JS
  move past-events and resources pages to subdirs