Update package distribution

* Move package documentation to root level
* Simplify MANIFEST.in
Update development and CI configurations

* Simplify CI matrix
* Implement code analysis
* Check distribution metadata
* Implement code coverage validation
* Add Coveralls badge to documentation
Fix code analysis and add missing part on CI
Run distribution metadata check only on QA
Depend on Products.CMFPlone and not on Plone
Remove dependency on unittest2
Fix package dependencies
Fix CI configuration
Use View permission on viewlets to avoid security failures into viewlet
  if anonymous try to display non public parts of site.
ignore eclipse files
Merge pull request #26 from tdesvenain/master

Use View permission on viewlets
Fix changelog
Preparing release 2.0b1
Back to development: 2.0b2
Allow larger images to be sent to Facebook
Update changelog
Split tests
Cache with modification date
Remove unused code
Increase test coverage