Complete build now works

- Marks build as complete
- Deletes temporary BuildItem objects
- Preselects the part's default_location if there is one
- Creates a new stockitem in the selected location

InvenTree/templates/modal_form.html

@@ -1,3 +1,6 @@
+{% block pre_form_content %}
+{% endblock %}
+
 {% if form.non_field_errors %}
 <div class='alert alert-danger' role='alert' style='display: block;'>
   <b>Error Submitting Form:</b>
@@ -11,4 +14,7 @@
   
   
   {% crispy form %}
-</form>
+</form>
+
+{% block post_form_content %}
+{% endblock %}