'reverse' option for dictsort
diff --git a/jinja2/filters.py b/jinja2/filters.py
index da15a1a..2496d3a 100644
--- a/jinja2/filters.py
+++ b/jinja2/filters.py
@@ -203,7 +203,7 @@
          if item])
 
 
-def do_dictsort(value, case_sensitive=False, by='key'):
+def do_dictsort(value, case_sensitive=False, by='key', reverse=False):
     """Sort a dict and yield (key, value) pairs. Because python dicts are
     unsorted you may want to use this function to order them by either
     key or value:
@@ -213,6 +213,9 @@
         {% for item in mydict|dictsort %}
             sort the dict by key, case insensitive
 
+        {% for item in mydict|dictsort(reverse=true) %}
+            sort the dict by key, case insensitive, reverse order
+
         {% for item in mydict|dictsort(true) %}
             sort the dict by key, case sensitive
 
@@ -232,7 +235,7 @@
             value = value.lower()
         return value
 
-    return sorted(value.items(), key=sort_func)
+    return sorted(value.items(), key=sort_func, reverse=reverse)
 
 
 @environmentfilter