fixed documentation of clip(TinyVector) and relatives
fixed another typo in ForwardIteratorFacade
added vectorial_distance.hxx and tests
separableVectorDistance(): result vectors do not include possible pixel pitch
Added tests for eccentricity transform and eccentricity centers.
Added python bindings for eccentricity transform.
Added python bindings for eccentricity centers.
fixed clip(TinyVector) and added test
refactored boundaryMultiDistance()
added boundaryVectorDistance() and tests, refactored separableVectorDistance()
updated boundaryMultiDistance() Python bindings
added more tests
Merge branch 'gsoc-integration' of https://github.com/dagophil/vigra into gsoc-integration