math/cminpack: Update to 1.3.14

ChangeLog: https://github.com/devernay/cminpack/releases/tag/v1.3.14

• Replace examples/crosscheck.sh with examples/crosscheck.py (no /bin/sh dependency); add examples/compare.py and examples/driver_check.py. Wire an informational cross-check into CMake/CTest via the CMINPACK_CROSSCHECK option. Python 3 is optional in both build systems: when absent only the cross-check is skipped, with a disclaimer.
• Fix a compile error in examples/tenorm_.c (pass dpmpar_ its index by pointer, the FORTRAN/f2c calling convention).
• Document the numerical differences from FORTRAN MINPACK and the test setup in the README and HTML docs; correct the enorm.c comments (the divergence is FMA, not the rdwarf/rgiant scaling constants).