Requesting review of new interchangeable BLAS components

[Jason Bacon <outpaddling%yahoo.com@localhost>]

As some of you may recall, Thomas Orgis has developed a new set of 
BLAS/LAPACK packages and an mk file that allow both users and package 
maintainers to interchange BLAS/LAPACK implementations for any package.

The system currently supports Netlib BLAS and LAPACK, CBLAS, LAPACKE, 
and OpenBLAS single-threaded, OpenMP and pthreads.  Netlib is the 
reference implementation and the only one currently supported by 
pkgsrc.  OpenBLAS and some proprietary implementations like Intel's MKL 
can be an order of magnitude faster in some settings, so this is an 
important step forward for pkgsrc in scientific computing.  All 
implementations are meant to be highly compatible, though occasional 
regressions are inevitable.  The user and maintainer control knobs 
provided by this system offer an easy workaround for any issues that 
might arise with a particular implementation.

This has been years in the making, has undergone extensive discussion 
about optimal design, and has been extensively tested in the field.
We believe the system is ready for commit and would like to ask for any 
final comments before we proceed.

My plan for the initial commit is as follows:

1. Add mk/blas.buildlink3.mk from wip/mk.
2. Upgrade math/blas and math/lapack, the current Netlib packages, from wip
3. Revbump all dependent packages and modify their .includes to use 
mk/blas.buildlink3.mk instead of math/blas/buildlink3.mk or 
math/lapack/buildlink3.mk.

So at this time, we only need immediate review of 
wip/mk/blas.buildlink3.mk, wip/blas, and wip/lapack.

After completing these commits and verifying that everything is in 
order, we will add the new packages wip/cblas, wip/lapacke, 
wip/openblas, wip-openblas_openmp, and wip/openblas_pthread.  This will 
open the door to far better performance of scientific applications and 
new packages that require the C interface provided by cblas/lapacke.  ( 
BLAS/LAPACK are originally written in Fortran. )

Thanks,

    JB