Add a new permission for using Taxonomy Search

It would be nice to restrict the use of the module to particular roles. For example, I only want admins to use it so that they can quickly find particular terms in large vocabularies, and edit them. I have created a patch that allows this, by adding in a new permission and wrapping the taxonomy_search_search and form_alter functions in a user_access check (hopefully this is the right way to do it). This patch is against the 5.x-2.0 release.