Set unique map id per page in map_list

This words around the issue where a map is displayed twice while
loading more maps in the home page because while loading maps some
have been updated

umap/templates/umap/map_fragment.html

@@ -1,5 +1,5 @@
 {% load umap_tags %}
-    <div id="{{ prefix }}{{ map.pk }}" class="map_fragment"></div>
+    <div id="{{ unique_id }}" class="map_fragment"></div>
     <script type="text/javascript">
-        new L.U.Map("{{ prefix }}{{ map.pk }}", {{ map_settings|notag|safe }});
+        new L.U.Map("{{ unique_id }}", {{ map_settings|notag|safe }});
     </script>

umap/templates/umap/map_list.html

@@ -3,7 +3,7 @@
 {% for map_inst in maps %}
 <hr />
 <div class="col wide">
-    {% map_fragment map_inst prefix=prefix %}
+    {% map_fragment map_inst prefix=prefix page=request.GET.p %}
     <div class="legend"><a href="{{ map_inst.get_absolute_url }}">{{ map_inst.name }}</a>{% if map_inst.owner %} <em>{% trans "by" %} <a href="{% url 'user_maps' map_inst.owner.username %}">{{ map_inst.owner }}</a></em>{% endif %}</div>
 </div>
 {% endfor %}

umap/templates/umap/search.html

@@ -8,7 +8,7 @@
   <div class="wrapper">
     <div class="map_list row">
     {% if maps %}
-      {% include "umap/map_list.html" with prefix='search_map_' %}
+      {% include "umap/map_list.html" with prefix='search_map' %}
     {% else %}
         {% trans "Not map found." %}
     {% endif %}

umap/templatetags/umap_tags.py

@@ -50,11 +50,13 @@ def map_fragment(map_instance, **kwargs):
         'slideshow': {}
     })
     map_settings['properties'].update(kwargs)
-    prefix = kwargs.pop('prefix', None) or 'map_'
+    prefix = kwargs.pop('prefix', None) or 'map'
+    page = kwargs.pop('page', None) or ''
+    unique_id = prefix + str(page) + "_" + str(map_instance.pk)
     return {
         "map_settings": json.dumps(map_settings),
         "map": map_instance,
-        "prefix": prefix
+        "unique_id": unique_id
     }