Fixes for out of range next/prev links and tags

Add additional checks to not generate paginator, next and prev links, or rel next/prev tags if the current page out of range (greater than last page).

Added specs for all changes (paginator, next and prev links, rel next/prev tags).

We were seeing that on a particular page, we might only have 3 pages, but for some reason GoogleBot was coming along and indexing /page/100, /page/101, etc.  This might seem harmless at first, but what ends up happening is that when the page number is out of range, then GoogleBot gets stuck infinitely traversing the next links.

This bug fix should stop crawlers from infinitely crawling your website when the page is out of range.