Removed buggy -seppot output

ns() no longer computes forces, so the comment needs correcting.

dvdlambda was changed to an array at some point, but the output code
did not change in sync. So, that output has been broken in at least
4.6, and is always zero anyway. So the output code can go away.

A patch in master branch removes the useless parameters in the
neighbour-search code. When merging this patch into master branch,
eliminate the useless dvdlambda variable.

Fixes #1294

Change-Id: Iba48f549ee07f0ee1877035a9e506780439c8002
implemented plain-C SIMD macros for reference

This is mainly code reorganization.
Adds reference plain-C, slow, arbitrary width SIMD for testing.
Adds FMA for gmx_calc_rsq_pr.
Adds generic SIMD acceleration (also AVX or double) for pme solve.
Moved SIMD vector operations to gmx_simd_vec.h
The math functions invsqrt, inv, pmecorrF and pmecorrV have been
copied from the x86 specific single/double files to generic files
using the SIMD macros from gmx_simd_macros.h.
Moved all architecture specific nbnxn_kernel_simd_utils code to
separate files for each SIMD architecture and replaced all macros
by inline functions.
The SIMD reference nbnxn 2xnn kernels now support 16-wide SIMD.
Adds FMA for in nbnxn kernels for calc_rsq and Coulomb forces.

Refs #1173

Change-Id: Ieda78cc3bcb499e8c17ef8ef539c49cbc2d6d74d
Fixes #1312 uninitialized error in g_enemat.

Change-Id: Ia0ac6d095dd560f08576aad1b435c92b6de52b3b
Update management of linear algebra libraries

Management of detection and/or linking to BLAS and LAPACK libraries is
re-organized. The code has migrated to its own module. This will
help future extension and maintenance. This version communicates
things that are newsworthy and stays out of the way when nothing
is changing.

We no longer over-write the values specified by the user for
GMX_EXTERNAL_(BLAS|LAPACK). Previously, this was used to signal
whether detection succeeded, but that does not really get the job
done. Instead, the user is notified that detection failed (repeatedly,
if they deliberately set such an option on).

Correct usage and expected behaviour in all cases is documented both
in the code and the install guide.

The user interface is pretty much unchanged. We still don't offer full
configurability (e.g. MKL for FFTs must use MKL for linear algebra
unless GMX_*_USER is used, and the only way to get MKL for linear
algebra is to use it for FFTs). The size of any performance difference
is probably very small, and if the user really needs mdrun with
certain FFT and tools with certain linear algebra library, they can do
two configurations. Note that mdrun never calls any linear algebra
routines (tested empirically)!

Expanded the solution of #771 by testing that the user supplied
libraries that actually work. If not, we emit a warning and try to use
them anyway.

We also now check that MKL really does provide linear algebra
routines, and fall back to the default treatment if it does not.

Refs #771,#1186

Change-Id: Ife5c59694e29a3ce73fc55975e26f6c083317d9b
Find mkl.h on more icc versions

Refs #1110

Change-Id: I0b6bc2497fc2a504b6c29b0697ee9e354fe6cffd