Remove <noscript> from www.dartlang.org, to avoid occasional formatting problems.

To test, compare these two:

  http://noscript.dart-lang.appspot.com/tools/editor/troubleshoot.html
  http://www.dartlang.org/tools/editor/troubleshoot.html

(You might have to reload a few times to make the formatting issue show up in the latter page.)

Review URL: https://chromiumcodereview.appspot.com/14202002