Building against static Python interpreter

[jakirkham]

If the Python interpreter is built statically on Unix, there is no need to link to the Python dynamic library (in fact it will cause segfaults). Vigranumpy (at least in the 1.11.1 release) still picks up the dynamic library during the build in this case, which causes problems. Would be good if it could either provide an option to disable use of the dynamic library or better yet detect static linkage and skip including the dynamic library. FWIW here's the workaround we used to bypass the dynamic library in conda-forge.

[stuarteberg]

As I mentioned in conda-forge/vigra-feedstock#43 (comment), I have concerns about the proposed workaround. I think we should avoid -undefined dynamic_lookup if possible. I've had only negative experiences with that linker setting in the past.