It is planned to add another matrix type for the tests.
The names of the prepare routines have become a bit inconsistent and
confusing. Thus the rename

Anything if it makes Andreas happy :)

We got reports from a user that there were troubles with certain domain
decompositions. So far the tests only looked at (approximately) square
decompositions in column-major process order.

Now, a new class of tests loops over all possible decompositions
(row * col) for a given number of total tasks.

So far, we can not confirm that there are any problems, all
possibilities work as expected.

Previously we checked ortonormality of eigenvectors by comparing
the matrix S^T * S to identity matrix. The new feature is also
checking just the diagonal of the matrix S^T * S. By that we get
the information, how far are the eigenvectors from having length 1.
If it turns out to be important, we could try to normalize them
at the end of elpa, which is simple (in contrast with enforcing
better orthogonality).

- Remove all use of ELPA internal modules, the test programs now
  only use the public ELPA API. This is now enforced, by hiding the
  private modules

- Prefix all test internal modules with "test_" to make it really
  clear that these modules are not to be used by users.

The legacy API is has been (internally) ported to use the new interface.
The intent is that users of the legacy API do not have to change their
codes.

Next step is to completely adapt the .gitlab-ci.yml file

They are in a sad state, it's all copy&paste and chaos. This commit
only touches the surface so far.

Conflicts:
	src/elpa1_compute_complex_template.X90

gpu tests for elpa 1 added

Conflicts:
	src/elpa1.F90
	src/elpa1_tridiag_real_template.X90
	src/elpa_c_interface.F90
	test/Fortran/test_complex.F90
	test/Fortran/test_complex_single.F90
	test/Fortran/test_real.F90
	test/Fortran/test_real_single.F90
	test/Fortran/test_real_with_c.F90

Some of the file names were too long, automake then dropped these
files when doing "make distcheck"

This solves issue #14

library

It the configure option "--enable-single-precision" is specified,
ELPA will also be build for single precision usage. The double precision
and single precision will be available at the same time with names
"solve_evp_real_1stage_double" or "solve_evp_real_1stage_single" and
so on...

This change immplied some major refactoring of the ELPA code:
1.) functions/procedures had to be renamed with suffix "_double"

2.) If necessary the same functions have to be available with suffix
"_single"

3.) Variable kind definitions have to be consistent with the
intented use

To avoid uneccessary code duplication this is done (most of the time)
with preprocessor string substitution.

The documentation has been updated.

NOT SUPPORTED are at the moment:

- single precision usage of ELPA2 with kernels, others than "generic"
  and "generic_simple"

- single precision usage of GPU

files

The test programs include the same template now, the
printed messages are thus unified

The configure flag "--enable-shared-memory-only" triggers a build
of ELPA without MPI support:

- all MPI calls are skipped (or overloaded)
- all calls to scalapack functions are replaced by the corresponding
  lapack calls
- all calls to blacs are skipped

Using ELPA without MPI gives the same results as using ELPA with 1 MPI
task!

This version is not yet optimized for performance, here and there some
unecessary copies are done.

Ths version is intended for users, who do not have MPI in their
application but still would like to use ELPA on one compute node

With the configure option "--enable-single-precision" ELPA1 is build
with single-precision (half-words) only.

The best precision in single-precision (float or complex) is
2^-23 ~ 1.2e-7. The accuracy of the error residual of ELPA1 in
single-precision mode is of the order 1e-4 to 1e-5. The orthogonality of
the EV's is fullfilled up to about ~1e-6.

Thus the precision of ELPA1 in single-precision mode is roughly 100 -
1000 times less than the best achievable precison. This is consistent
with the double-precision mode, where also a factor of 100 - 1000 less
precision than the theoretical best one is found.

The float EVs are identical to the double EVs to at least 1e-2, the
precision of the EVs is thus about 1e-7/1e-2 = 1e5 times lower than the
best theoretical precision. If the same holds for the double precision
calculations, this implies that the double precision results can also
be only trusted on the level 1e-11 (5 orders of magnitude larger
than the best theoretical precision)

The best speed-up compared to the double precision calculation is
a factor of two. This is by far not achieved yet, since the singl
precision version is not at all optimized at the moment

The Fortran variable declerations "variable type*[4,8,16]" is non
Fortran standard. It might cause problem in the future.
Furthermore, the usage of Fortran and C togehther is more clean
if variables are defined according to C variable types.

This is done, now for all the test programs

This commit does not change the interfaces defined in ELPA_2015.11.001 !
All functionality is available via the interface names and definitions
as in ELPA_2015.11.001

But some new interfaces have been added, in order to unfiy the
references from C and Fortran codes:

- The procedures to create the ELPA (row/column) communicators are now
  available from C _and_ Fortran with the name "get_elpa_communicators".
  The old Fortran name "get_elpa_row_col_comms" and the old C name
  "elpa_get_communicators" are from now on deprecated but still available

- The 1-stage solver routines are available from C _and_ Fortran via
  the names "solve_evp_real_1stage" and "solve_evp_complex_1stage".
  The old Fortran names "solve_evp_real" and "solve_evp_complex" are
  from now on deprecated but still functional.

All documentation (man pages, doxygen, and example test programs) have
been changed accordingly.

This commit implies a change in the API versioning number, but no
changes to codes calling ELPA (if they have been already updated to the
API of ELPA_2015.11.001)

- the contact email is now: elpa-library@mpcdf.mpg.de
- the official website is now hosted at http://elpa.mpcdf.mpg.de