Simpletest module fixes for new core

In the attached patch I fixed problems with running simpletest module on latest core after code freeze
Changes:
drupal_reporter.php
- new way of creating forms new function outside of the class returns $form
- removed & when calling writeToLastField because of Call-time pass-by-reference has been deprecated warning
drupal_test_case.php
- setFieldByName call is changed fields on forms now don't use edit[fieldname] anymore
simpletest.module
- in t function calls when links are inserted I put ! instead of %
- and because the forms dont have edit[] anymore $edit = $_POST instead of $edit = $_POST['edit']

Please review the code.