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.html

@@ -5,7 +5,7 @@
 {% endcomment %}
 
 
-<form method="post" action="{{form.action_url}}" {% for attr_key, attr_val in form.form_attrs.items %} {{attr_key}}="{{attr_val}}"{% endfor %}>
+<form method="post" action="" {% for attr_key, attr_val in form.form_attrs.items %} {{attr_key}}="{{attr_val}}"{% endfor %}>
   {% csrf_token %}
     <div class="modal-header">
         <h5 class="modal-title">{{form.form_title}}</h5>