cad/openvsp: update to 3.17.1

Removing one patch accepted upstream.

ChangeLog:
http://openvsp.org/blogs/announcements/2019/07/08/openvsp-3-17-1-released

Features:

• Calculate average and weighted chord and solidity for props
• Expand API coverage
• Improve CMake to help FLTK build on Linux
• Add names to exported STEP files.

Library Update:

• Update GLM to 0.9.9.5

Fixes:

• Fix skin friction equations
• Multiple FEA GUI Fixes
• Don't assume FEA skin is first component
• IGES Structure Parm Name Collision (Thanks Jim Fenbert)
• STEP Structure missing options
• Overlapping Prop XSecs
• Register missing attachment enums w/ API
• Protect 4-dig airfoils from out of bounds parms
• Improve ResetRemapID behavior
• Fix problems with prop and file airfoils
• Add missing GUI handling of read-file XSecs for body of revolution
• Silence a bunch of warnings
• Use equal arc len parameterization for super ellipses