make sure the format placeholder is valid for Python 2.6 (thanks @davidia)
another python 2.6 compatibility fix
Merge branch 'master' into fix-setup-py26
Merge branch 'master' into fix-setup-py26
.travis.yml file fixed for Python 2.6
Merge pull request #19 from dpinte/fix-setup-py26

Various fixes for Python 2.6 support