Fixes linkage with FFTW + MKL for BLAS/LAPACK

The order of linking was incorrect, when using both mkl and fftw
causing the mkl fftw wrapper to be used instead of fftw itself.

Removes all unnecessary transitive libraries (cmake adds those
automatically). Simplifies the target_link_libraries lines, and
makes it much easier to change the fft/blas link order.

Only remaining transitive libraries are gmx/md for binaries. This
is required because OpenMP_LINKER_FLAGS needs to be at the end
but transitive libraries are added at the end. Thus without listing
gmx/md manually the order is incorrect.

Also fixes that nbnxn_cuda has cuda_tools listed as library
dependency. Was prior working without it but now is needed and is
also anyhow the more corect way to do it.

Fixes #1067

Change-Id: I639b16f1460d27a15eb72cc00674c041266f6624
Merge "Fixes linkage with FFTW + MKL for BLAS/LAPACK" into release-4-6