Initial work to support Python 3.3+

This updates most of the code to be forward-compatible with Python 3.3 and
3.4 while still continuing to support 2.6 and 2.7. It **drops** support for
Python 2.5.

Python 3 support is added for common Boto modules (`boto/*.py`) as well as
S3, SQS, Kinesis and CloudTrail. Several other modules may work but have
not been thoroughly tested.

The `tox` configuration has been updated to run tests for all supported
environments, and for now a whitelist is used for Python 3 unit tests.

A new porting guide is included to help community members port other
modules to Python 3, and both the README and Sphinx index list which
modules currently support Python 3.

1 files changed, 3 insertions, 2 deletions

diff --git a/boto/ecs/item.py b/boto/ecs/item.py
index 624088dc..5244fbea 100644
--- a/boto/ecs/item.py
+++ b/boto/ecs/item.py
@@ -23,6 +23,7 @@
 import xml.sax
 import cgi
 from StringIO import StringIO
+from boto.compat import six
 
 class ResponseGroup(xml.sax.ContentHandler):
     """A Generic "Response Group", which can
@@ -141,14 +142,14 @@ class ItemSet(ResponseGroup):
         if self.iter is None:
             self.iter = iter(self.objs)
         try:
-            return self.iter.next()
+            return six.advance_iterator(self.iter)
         except StopIteration:
             self.iter = None
             self.objs = []
             if int(self.page) < int(self.total_pages):
                 self.page += 1
                 self._connection.get_response(self.action, self.params, self.page, self)
-                return self.next()
+                return six.advance_iterator(self)
             else:
                 raise