Keep zc.buildout in 1.x branch
Fix package distribution
Update development buildout

Extend from standard configuration
Add Travis CI configuration (refs. #23)

* Implement CI over Plone 4.0/4.1 (Python 2.6) and Plone 4.2/4.3 (Python 2.7)
* Add support for Coveralls
* Add CI and Coveralls status badges on package documentation