Adding a no results state to 404 pages

I refactored the code a little to basically set a default version of the page to take into account when there were no results found, or if the path they hit happened to also be a term we are filtering, like /actnow, for example. This way the 404 page will always show something, unless of course, we disable the 404 functionality in rare cases. 

Fixes #3428 

@aaronschachter @deadlybutter