This preserves the scrolltop state of the user when they enter into
an integration's specifics, so when they exit out it scrolls them
back down the page.
Fixes: #4424.
This fixes the hubot text that still stays when you transition to
integration details along with fixing the first animation that is
choppy and previews briefly before fading in.
Fixes#4210.
Checking by href is a flawed approach due to the fact that hashes
are included in the href and will throw off the results of
returning the last block in a path. The window.location.pathname
property is a much better indicator of the current path.
Brock Whittaker