cad/stepcode: update to 0.8.2

ChangeLog: https://github.com/stepcode/stepcode/releases/tag/v0.8.2

Build fixes

• dependency fixes for expparse / expscan.
• handle newer clang compilers
• more robust parallel building

Relocation of headers and explicit directory prefixes

• client codes should now include one directory (for example, /usr/include/stepcode) and specify headers in their code using path/header.h (for example, #include <clstepcore/sdai.h>) previous releases required explicit listing of all stepcode folders due to internal header include directives - this has been corrected