ArithmeticalDSS

I separated the code of the arithmetical DSS recognition into : 
- ArithmeticalDSL : representation of a DSL
- ArithmeticalDSS : representation of a DSS
They are both models of CPointFunctor and CConstBidirectionalRange.
- ArithmeticalDSSComputer : wrapper around ArithmeticalDSS for the dynamic recognition of DSSs along sequence of points. 

A doc page has been added to the geometry package. 

Moreover, this PR fixes #580 and #493