Add another small encoding test for xhtml_escape.
Remove obsolete comment about twitter's support for callback urls.
Release note updates.
Move next release notes to v3.1.
Set version to 3.1.
WSGI specification requires that close() be called on iterable no matter what happens.
Set master branch version to 3.2.dev1
Merge pull request #824 from GrahamDumpleton/master

WSGI specification requires that close() be called on iterable no matter what happens.