Test QR codes, which work just fine.
Added ``preserveAspectRatio`` to ``img`` tag flowable.

The attribute was already supported for the ``image`` tag.
Preparing release 2.2.0
Back to development: 2.2.1
- Make the number of max rendering passes configurable by exposing the setting
  in the API.

- Added `align` attribute to ``img`` tag.
Preparing release 2.2.1
Back to development: 2.2.2
- Added ``title``, ``subject``, ``author``, and ``creator`` attributes to
  ``document`` element. Those are set as PDF annotations, which are now
  commonly used to hint viewers window titles, etc. (Those fields are not
  available in RML2PDF.)
- Added ``title``, ``subject``, ``author``, and ``creator`` attributes to
  ``document`` element. Those are set as PDF annotations, which are now
  commonly used to hint viewers window titles, etc. (Those fields are not
  available in RML2PDF.)
Preparing release 2.3.0
Back to development: 2.3.1
Fix #14 by replacing pyPdf usage with PyPDF2. Although tox reports ten test failures under both py26 and py27, the same ten tests fail without this change.
Make sure that we are referecning the right element during error reporting.
``registerFontFamily`` never worked until now, since the directive was not
properly registered.
Preparing release 2.3.1
Back to development: 2.3.2
Merge branch 'master' of github.com:NextThought/z3c.rml into NextThought-master
Fix failing test. Not sure how this passed before.
Small wording improvement.
Preparing release 2.4.0