Add forgotten methods in COBANaivePlane and COBAGenericNaivePlane.
Add Chord naive plane recognition algorithm.
Merge branch 'master' of github.com:DGtal-team/DGtal into FixCOBA

This is to check that the fusion is valid.
Updating documentation.
Changing names of plane recognition algorithms to ...NaivePlaneComputer. Fixing some doc.
Fix default parameter threshold in examples greedy-plane-segmentation*.
Add example for ChordNaivePlane.
Add primitive ParallelStrip for COBA algorithm.
Add diagonal width in example.
Add primitive to COBANaivePlaneComputer. Update examples.
Add primitives to ChordNaivePlaneComputer.
Change default values in testMultiMap-benchmark to speed up tests.
Fix bug in COBANaivePlaneComputer when extending with extend(it,itE) an empty plane. Check extension methods in testCOBANaivePlaneComputer.
Update testChordNaivePlaneComputer in order to check extension with many points at the same time.
Extend ParallelStrip to large/strict inequalities.
Adding documentation for plane recognition.
New documentation for plane recognition.
Add primitive concepts.
Add image for viewer-7bis-planes.
Update doc.