[Discuss-gnuradio] volk work - please test

[Josh Blum]

Hey list,

Nick Foster and I have done a lot of work to simplify and generalize the
VOLK build system.

* Removed old autotools related generalization
* Fixes for stand-alone building of VOLK
* AVX enabled detection support on MSVC
* Building and generation now share common code
* The architecture specifications:
** feature availability checks are fully specified
** required compiler flags listed with compiler association
* Generated c/h files have corresponding templates
** generator code is drastically more readable/editable

The branch is here:
https://github.com/guruofquality/gnuradio/tree/volk_work

I would appreciate anyone testing the branch, especially on weird machines:
* does it build?
* do the unit tests pass?
* does volk detect correctly?

My opteron says:
$volk/lib/test_all
Running 88 test cases...
Using Volk machine: sse4_a_64_orc

This branch will pave the way for for future work for generalizing
alignment, and head and tail cases for VOLK kernels.

Thanks!
-Josh