Merge branch 'issue/unused_macros_dim_max' into 'master'

ref:staging/dune-uggrid The macros DIM_MAX and DIM_OF_BND_MAX are not used
anywhere and the DIM_MAX macro conflicts with macros from other libraries. So
they are simply removed. The corresponding `#undef DIM_MAX` should be removed
from dune-grid.

See merge request [!135]

  [!135]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/135

Merge branch 'build-tetrahedron-refrules-into-library' into 'master'

ref:staging/dune-uggrid The TET_RULESET compile-time option could be used to
load tetrahedron refinement rules from RefRules.data, however this requires to
locate the file at run-time. This was too inconvenient.

Instead generate RefRules.cc from RefRules.data including the refinement rules
and use that.

See merge request [!134]

  [!134]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/134

The `TET_RULESET` compile-time option could be used to load
tetrahedron refinement rules from `RefRules.data`, however this
requires to locate the file at run-time.  This was too inconvenient.

Instead generate `RefRules.cc` from `RefRules.data` including the
refinement rules and use that.

Merge branch 'use-std-abs' into 'master'

See merge request [!133]

  [!133]: Nonestaging/dune-uggrid/merge_requests/133

Merge branch 'use-standard-deprecated-attribute' into 'master'

See merge request [!132]

  [!132]: Nonestaging/dune-uggrid/merge_requests/132

Merge branch 'cleanup-33' into 'master'

See merge request [!131]

  [!131]: Nonestaging/dune-uggrid/merge_requests/131

This addresses the following compiler warning from GCC 9:

    gm/ugm.cc:1247:12: warning: unused variable ‘f’ [-Wunused-variable]

This addresses the following warning from GCC 9:

    parallel/ddd/xfer/unpack.cc:410:11: warning:
    ‘curr’ may be used uninitialized in this function [-Wmaybe-uninitialized]

The variable is currently not used; just remove it as the include for
`DUNE_UNUSED` is sometimes missing.

Merge branch 'fix_warning_set_but_unused_nSendMsgs' into 'master'

ref:staging/dune-uggrid

    Added the attribute "DUNE_UNUSED" to the variable "nSendMsgs" to avoid the
    warning:"variable 'nSendMsgs' set but not used".

See merge request [!125]

  [!125]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/125

Merge branch 'change_function_structure_gm_rm' into 'master'

ref:staging/dune-uggrid Changed the structure of three functions in "gm/rm.cc"
that threw a warning.

Deleted the variable TBFR which is now unused in each of the functions. Moved
the declaration of variables to their initialization and added a new "switch
case" to avoid an if condition in each function.

See merge request [!128]

  [!128]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/128

Moved declarations of variables to their initialization and restricted
their scope.

Added a new case for "imin" to get rid of the if condition and deleted
the now unused variable "TBFR".

Merge branch 'ci-build-with-debug' into 'master'

See merge request [!129]

  [!129]: Nonestaging/dune-uggrid/merge_requests/129

Merge branch 'fix/remove-include-no-longer-around' into 'master'

See merge request [!130]

  [!130]: Nonestaging/dune-uggrid/merge_requests/130

Merge branch 'fix_warnings_set_but_unused' into 'master'

ref:staging/dune-uggrid I fixed all warnings "-Wunused-but-set-variable" by
gcc.

    I added the attribute "DUNE_UNUSED" to the variables to avoid the warnings. 

See merge request [!126]

  [!126]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/126

````
I added the attribute "DUNE_UNUSED" to the variable "count" to avoid the
warning: "variable set but unused". This warning was only occuring in
the compiler-test "gcc-8-noassert-17"
````

Merge branch 'fix_warning_set_but_unused_errorflag' into 'master'

ref:staging/dune-uggrid

    I added the attribute "DUNE_UNUSED" to the variable "errorflag" to avoid the
     warning: "variable 'errorflag' set but not used".

See merge request [!124]

  [!124]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/124

````
Added the attribute "DUNE_UNUSED" to the variable "nSendMsgs" to avoid a
warning.
````

````
I added the attribute "DUNE_UNUSED" to the variable "errorflag" to avoid the
 warning: "variable 'errorflag' set but not used".
````

Merge branch 'fix_special_green_rule_17_22' into 'master'

ref:staging/dune-uggrid As written the condition read

        (TAG(theElement) == PYRAMID && NSONS(theFather)==9) || other_condition

that is `ECLASS(theElement) == GREEN_CLASS` was not always checked. We assume
this was not intentional.

See merge request [!122]

  [!122]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/122

As written the condition read
```
	(TAG(theElement) == PYRAMID && NSONS(theFather)==9) || other_condition
```
that is `ECLASS(theElement) == GREEN_CLASS` was not always checked.
We assume this was not intentional.

Merge branch 'fix/unused-variables' into 'master'

See merge request [!121]

  [!121]: Nonestaging/dune-uggrid/merge_requests/121

Merge branch 'install-missing-headers' into 'master'

See merge request [!120]

  [!120]: Nonestaging/dune-uggrid/merge_requests/120

Merge branch 'ci/centralize-config' into 'master'

ref:staging/dune-uggrid This MR switches the CI configuration to use the
common job templates defined in core/ci-config.

See merge request [!119]

  [!119]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/119

Merge branch 'cleanup/move-COMPARE_RECORD-into-UGDIM-namespace' into 'master'

ref:staging/dune-uggrid This silences a compiler warning from GCC when
building programs with LTO where GCC sees two definitions of COMPARE_RECORD
(for 2d and for 3d):

    ../gm/refine.cc:3450:8: warning: type ‘struct compare_record’ violates the C++ One Definition Rule [-Wodr]
    ../gm/refine.cc:3450:8: note: a different type is defined in another translation unit
    ../gm/refine.cc:3453:12: note: the first difference of corresponding definitions is field ‘elem’
    ../gm/refine.cc:3453:12: note: a field of same name but different type is defined in another translation unit
    ../ug/gm.h:1644:24: note: type ‘union ELEMENT’ should match type ‘union ELEMENT’

See merge request [!118]

  [!118]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/118