fixed url glitch, added parent url

templates/svxfile.html

@@ -1,6 +1,6 @@
 <!-- svxfile.html - this text visible because this template has been included -->
 {% extends "base.html" %}
-{% block title %}{{ title }}{% endblock %}
+{% block title %}{{ survexfile }}{% endblock %}
 
 {% block head %}
 <!--  Should we wait until CodeMirror 6.0 is available https://codemirror.net/6/ -->
@@ -38,9 +38,9 @@ $(document).ready(function()
 
 {% block content %}
 {% if warning %}
-<h1 style="color: red">Survex Template - will save as file '{{ title }}.svx'</h1>
+<h1 style="color: red">Survex Template - will save as file '{{ survexfile }}.svx'</h1>
 {% else %}
-<h1>Survex File: {{ title }}</h1>
+<h1>Survex File: {{ survexfile }}</h1>
 {% endif %}
 
 {% if svxincludes %}
@@ -68,10 +68,10 @@ $(document).ready(function()
 
 {% if logmessage %}
     {% if has_3d %}
-        <p>Click here to view the <a href='{% url "threed" title %}'>3d file</a> produced as output</p>
+        <p>Click here to view the <a href='{% url "threed" survexfile %}'>3d file</a> produced as output</p>
     {% else %}
-        <p><b>No 3d file generated. There was an ERROR<br>Read the full <a href='{% url "svxlog" title %}'>.log file</a>
-        the <a href='{% url "err" title %}'>.err file</a> and fix this .svx file</b></p>
+        <p><b>No 3d file generated. There was an ERROR<br>Read the full <a href='{% url "svxlog" survexfile %}'>.log file</a>
+        the <a href='{% url "err" survexfile %}'>.err file</a> and fix this .svx file</b></p>
     {% endif %}
 <!--    <pre>
 LOGMESSAGES
@@ -81,7 +81,7 @@ LOGMESSAGES
 {% endif %}
 </div>
 underground survey length: {{svxlength|floatformat:2}} metres<br />
-
+parent survex file <a href="/survexfile/{{ survexfile.cave.survex_file }}">{{survexfile.cave.survex_file}}</a> for this cave <br /> 
 {% for sb in svxblocks %}
 block:({{sb}}) has parent block:<a href="{{sb.parent.path}}">({{sb.parent}})</a>
 {% empty %}