Modal and other tweaks

* removes WIKI_URL, replaces with HELP_LINK since it was the same before as well
* refactors modal form processing (process_request())
   * modal form can now display errors directly inside the modal (as intended by the devs)
   * modals now properly support the GET-POST workflow that is intended by the devs. More information here: https://github.com/trco/django-bootstrap-modal-forms/issues/183
* Improves label-field linking in generic_table_form_body.html
* removes isDeleteForm attribute from modal_form_script.html

templates/modal/modal_form_script.html

@@ -10,7 +10,6 @@
         $(".{{btn_class}}").each(function () {
             $(this).modalForm({
                     formURL: $(this).data("form-url"),
-                    isDeleteForm: {{modal_reload_page}},
                 }
             );
         });