Due to an error, on systems where AVX-2 (FMA) was supported, also
the "pure" AVX kernels used FMA instructions. This has been fixed
now

* Switch to a simple non-WY algorithm
* Unify real and complex cases
* Update reduction kernel
* Use __shfl_xor_sync for warp reduce (CUDA 9+)
* Support 2^n block size, n = 1,2,...,10
* Use templates when possible
* Clean up unused CUDA functions
* Increase default stripe width when using GPU

ELPA can now link agains a 64bit integer verion of BLAS/LAPACK.
Currently this only works if ELPA is compiled with MPI=OFF!

The 64bit support is not available in the legacy interface

On heterogenous cluster, of nodes with different CPUs the _experimental_
feature (--enable-heterogenous-cluster-support) can be used:

It compares the (Intel) cpuid set of all CPUs which are used by ELPA MPI
processes and finds the SIMD instruction set, which is supported by all
used CPUs. The ELPA 2stage back-transformation kernel (a.k.a "kernel")
will be set accordingly on all MPI processes.

This feature, can override the setting of the kernel done previously by
the user!

At the moment it will only work for Intel CPUs, i.e. clusters consisting
of nodes with Intel CPUs and e.g. AMD CPUs are at the moment _NOT_
supported.

Since this is an experimental feature, it might be dropped again in the
future, if it turns out not to be useful for the users

Obviously, recent versions of automake decided to filter out
an "test_" string which led to some surprises