Makes a small change to how PREFIX is stored, to make it more compatible with conda builds
Fixes an issue in the makefile that would add C++ flags to C compiler invocation (I promoted getstrex.c to a .cpp file to make the fix simple; see the note in that commit).
Thank you. I'll keep the issue with .c files in mind... I think that's the only instance, at least at present, where it would be an issue for Find_Orb and most related code.
This PR fixes two issues: