Log message:
math/blas, math/lapack: Install interchangeable BLAS system

Install the new interchangeable BLAS system created by Thomas Orgis,
currently supporting Netlib BLAS/LAPACK, OpenBLAS, cblas, lapacke, and
Apple's Accelerate.framework.  This system allows the user to select any
BLAS implementation without modifying packages or using package options, by
setting PKGSRC_BLAS_TYPES in mk.conf. See mk/blas.buildlink3.mk for details.

This commit should not alter behavior of existing packages as the system
defaults to Netlib BLAS/LAPACK, which until now has been the only supported
implementation.

Details:

Add new mk/blas.buildlink3.mk for inclusion in dependent packages
Install compatible Netlib math/blas and math/lapack packages
Update math/blas and math/lapack MAINTAINER approved by adam@
OpenBLAS, cblas, and lapacke will follow in separate commits
Update direct dependents to use mk/blas.buildlink3.mk
Perform recursive revbump

Log message:
py-mol: use buildlink for py-numpy

Log message:
*: recursive bump for libffi

Log message:
Changed PYTHON_VERSIONS_INCOMPATIBLE to PYTHON_VERSIONS_ACCEPTED; needed for \ 
future Python 3.8

Log message:
Switch packages using GLUT to FreeGLUT.

Start building FreeGLUT with GLUT compatibility on.

- GLUT's maintainance state is much worse than FreeGLUT's, with no
  substanital commits since 2011.
- GLUT can no longer be consider a core component of Mesa or X11.
- Nobody except us seems to be using it...

Other vendors still shipping GLUT:
- GoboLinux, T2 SDE, PLD Linux

Revbump packages using GLUT or freeglut by default.

Log message:
Revbump after updating graphics/glew

Log message:
fix some whitespace, mostly introduced in the previous
python 3.4 / 3.5 removal commit.

Log message:
Omit mentions of python 34 and 35, after those were removed.

- Includes some whitespace changes, to be handled in a separate commit.