Update CI configuration

- Simplify configuration
- Use zc.buildout from 1.x branch
- Remove timeout parameter (this is not an issue anymore)
- Add debug information in case of failure
Allow failures under Plone 4.1 (refs. #36)
Fix CI configuration
Avoid browser cache  (Return code 304 Not Modified)
simplified code a little bit
factored out cropping for better testability
use Plone 4.3 for default buildout
started test for crop-view
override scaling view to keep crops on metadata change
implement scaling for plone.namedfile
Remove commented out version pins
fixed case where cropping annotation is none
we depend on plone.namedfile >= 2.0.1
document changes
adjust schema of test content so tests pass on 4.2 and 4.3
use latest seleium
specify version pinned egg plone.namedfile as test dependency
added test for plone 5.0
buildout and egg hygiene
remove buildout config which is a duplicate of buildout.cfg