Approx/Approx_SameParameter.cxx,hxx:
Class Approx_SameParameter refactoring. Logic is changed in many places to unify usage, simplify maintenance.
Method Curve2d() is changed to return Geom2d_Curve instead of Geom2d_BSplineCurve. Corresponding message is added to the upgrade guide.
.lxx file is merged into .hxx.
Tangent computation is extracted into special method.
Comparing number of sample points after CheckSameParameter(...) is added to define cases with projection fails.
Undesirable behavior when curves are not same parameterized is fixed.
Geom2dAdaptor/Geom2dAdaptor.cxx: treatment of offset curve is added
Adaptor3d/Adaptor3d_TopolTool.cxx: minor improvement of performance for BSpline surfaces with huge number of knots
Tests were modified according to new behavior of sameparameter algorithm
