Properly create the header links in the code review tool

Properly create the header links in the code review tool
https://bugs.webkit.org/show_bug.cgi?id=104037

Reviewed by Adam Barth.

Right now, we just prepend "header" to the two existing links and change
the first link to point to the header. The problem is that jQuery's prepend
method just prepends to each item in the jQuery object instead of adding
the item to the beginning of the list as this code assumed.

* code-review-test.html:
* code-review.js:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@136578 268f45cc-cd09-0410-ab3c-d52691b4dbfc