The threshold was used at several places to decide whether two values
are identical, on which side of a plane a point lies, and so on. The
strict value before lead to problems as some points were not considered
to be identical due to numerical reasons, although they were meant to
be identical. The larger threshold now solves the problems.

However, if more problems like this arise it should be checked whether
the threshold has to have different values at different places in the
code. Also additional code may be required to treat certain cases in
a special way.

nbsz determines the size of the region in reciprocal space considered
to construct the IBZ. Up to now this variable was set to 3 in julia.f.
But this value is not necessarily save. We now calculate a save but
also conservative value for this now local valiable nbszLocal in
brzone2.f90.

Also in this commit: Added build.* to .gitignore.

This commit and the 2 before made init/brzone2.f90 faster by
introducing or tightening constraints to filter out possible
boundary planes of the IBZ at an early stage of the algorithm.

I hope I didn't go too far.

Since the routine brzone featured many bugs that occured in special
cases I now reprogrammed the functionality of the routine in the
new subroutine brzone2. The new algorithm is simpler and should
be less vulnerable to the mentioned special cases. It also is slightly
slower. The new routine takes about 2 seconds.

By commenting the new routine out and the old one in both algorithms
can directly be interchanged.

...and a small initialization in init/inped.F90.

Removed preprocessor switches CPP_SOC, CPP_INVERSION, CPP_APW, CPP_CORE.
Only a single fleur executable is built.

This is a bug fix in response to the GitLab issue #49.

XML-Codepath has to be adjusted

git version to the executable. This is done by cmake generating a file
init/compileinfo.h with the required data. This file is included in init/compile_descr.F90 and
ignored by git.

...in collaboration with Uliana.

Time reversal symmetry is exploited to increase the number of symmetry
operations used for the generation of the Brillouin zone iff no inversion
symmetry is present. So far the inverse of each symmetry operation was
added, ignoring translation vectors. However, this could lead to further
identity symmetry operations which caused problems as this matrix has
to be excluded for several code parts.

The fix was developed in collaboration with D. Wortmann.

This fixes nothing.

I don't know whether I fixed this in the right code section or
if another code section would have been more appropriate.

This could lead to a faulty internal default enpara.

The missing initialization resulted in a failure in the PTO-SOC
test when debug options were used in the compile process.

Tests added: CuBandXML, CuDOSXML.

CuDOSXML does not yet pass.

Available special k points provided in inp.xml are used iff the file
band_inp is not present.

Also in this commit: Some mor copyright notices.

Note: self-defined k-point paths in inp.xml are not yet implemented.

...with inp.xml iff no enpara file is provided.

Also in this commit: Set the default vacuum energy parameter
to -0.25 Htr. It was -0.1 Htr at some places. The default value
is now stored in constants.f.