Rational angles
resolve issue #506
Merge branch 'master', remote-tracking branch 'origin' into FrechetSimplification
Merge branch 'masterDGtal' into FrechetSimplification
issue #543: update of the doc with bibtex cites
remove Rational Angle class from the PR
resolve conflicts when merging with masterDGtal
Merge pull request #559 from isivigno/FrechetSimplification

Frechet simplification