Automake does not easily allow to use the same source in a libtool
library and in a program

This solves issue #14

In case of single precision calculations the stripe_width needs to
be a multiple, which differs from the double precision by a factor of 2
since one needs 32 bytes alignment and the sizeof(float) and sizeof(double)
is different by a factor of two

This commit closes issue #18

The sub-kernels _8_ and _4_ were wrong
This also solves problems with single precision SSE Block 6 kernel,
since it also uses the Block 4 kernel

The correct type is "float complex" for single precision, not
"complex". Double precision should be "double complex"

This closes issue #17

In case of SSE/AVX/AVX2 it could happen that more than one kernel
(since some depend on other kernels, e.g. block 6 on block 4 and
block 2) were called

setting default kernels

This fixes issue #16: due to a mess in setting the default kernels,
several kernels were called at the same time, which produces wrong
results

The issue why these test programs are simply not build
has to be investigated