headers for the micronumpy multiarray and umath modules,
as used by https://bitbucket.org/pypy/numpy. They are needed by
downstream packages that depend on numpy, like matplotlib, but can
be slightly non-compatible with traditional numpy C-API use cases.

The trick to including these headers is in get_include, located in
numpy/lib/utils.py. They will be ignored by an upstream build of numpy
since the <site-packages>/numpy/core/include path will be used instead
