ctools_context_handler_edit_criteria() shouldn't force a module name

This function forces the module element in $form_state to be 'page_manager_task_handler', even though it is a part of ctools.module and not page_manager.module

It's probably fine to keep its current value as a sensible default, but I'd like it to check to see if a value has already been set before overwriting it.

Current:

<?php
function ctools_context_handler_edit_criteria($form, &$form_state) {
  ...
  $form_state['module'] = 'page_manager_task_handler';
  ...
}
?>

Proposed:

<?php
function ctools_context_handler_edit_criteria($form, &$form_state) {
  ...
  $form_state['module'] = (!isset($form_state['module'])) ? $form_state['module'] : 'page_manager_task_handler';
  ...
}
?>

Patch coming