Fixes <http://webkit.org/b/64125> TestFailures page seems slow to react on link clicks

Reviewed by Daniel Bates.

* BuildSlaveSupport/build.webkit.org-config/public_html/TestFailures/ViewController.js:
(ViewController.prototype.loaded): Create and store an h1 element for displaying the page's
title.
(ViewController.prototype._displayBuilder): Set the page's title and clear out any old
content immediately instead of waiting for the first set of results for the history
analyzer. As we receive new results from the analyzer we'll just clear out the main content
area and replace it with the new info.
(ViewController.prototype._displayTesters): Set the page's title and clear out any old
content immediately instead of waiting for the list of testers from the buildbot. Sprinkled
in a little use of our removeAllChildren helper, too.
(ViewController.prototype._setTitle): Added. Set's the page's title and the header text.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@90594 268f45cc-cd09-0410-ab3c-d52691b4dbfc