added compute_dp method to Curve class
adding lofted blade shape component
fixed import of check_gradient_unit_test
fixed file path in test_bladesurface
removed airfoil_depreciated.py file
blade_structure: radius renamed to blade_length
moved airfoil geometry stuff to geometry_vt.py and other small changes
fixed planform s that wasnt normalized
small fix to AirfoilShape
added @base to structure_vt
added SplinedBladeStructure and SplinedBladePlanform and configure methods
Merge pull request #41 from fzahle/develop

more turbine work