Add missing download_url and changelog

CHANGELOG

@@ -1,2 +1,4 @@
+* Allow egg installation
+
 Version 1.0.0 - 2008-11-17
 * Initial release

setup.py

@@ -27,6 +27,8 @@ setup(name='trytond_currency',
     author=info.get('author', ''),
     author_email=info.get('email', ''),
     url=info.get('website', ''),
+    download_url="http://downloads.tryton.org/" + \
+            info.get('version', '0.0.1').rsplit('.', 1)[0] + '/',
     package_dir={'trytond.modules.currency': '.'},
     packages=[
         'trytond.modules.currency',