[Fixes #8] Preserve python 2.7 back-compatibility

Author: afabiani

avatar/templatetags/avatar_tags.py

@@ -1,4 +1,8 @@
-from urllib.parse import urlencode
+try:
+    from urllib.parse import urlencode, urlsplit, urljoin
+except ImportError:
+    from urllib import urlencode
+    from urlparse import urlsplit, urljoin
 import hashlib