Sanitize content on copy in the code review tool

Sanitize content on copy in the code review tool
https://bugs.webkit.org/show_bug.cgi?id=104155

Reviewed by Tony Chang.

Always remove expand/header/annotate links. Provide an option
to remove line numbers as well. Store the option in localStorage so
people can always get whichever behavior they want.

A better solution would be to restructure the DOM, but that would require gutting
the whole code review tool and would make it difficult to include line numbers if
you wanted them.

* PrettyPatch/PrettyPatch.rb:
* code-review-test.html:
* code-review.js:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@136772 268f45cc-cd09-0410-ab3c-d52691b4dbfc