FileIO -> MeshLib::IO.

In order to make OGS more modular:
- The {read/write}Mesh{From/To}File.{h,cpp} are moved from FileIO to MeshLib/IO.
- The FileIO/Legacy folder was moved to MeshLib/IO/Legacy.
- Include paths are changed according the changes above.

Test output files are written to ${CMAKE_BUILD_DIR}/Tests/Data.

As a WIP data files have to be in ${CMAKE_SOURCE_DIR}../data

The results of this test are also included.

Corrected also the include paths for files in MathLib folder and SimpleTests/MatrixTests/ folder.

This is automatic replacement with
ag '(?<!std::)size_t(?!\w)' --ignore-dir=ThirdParty -l | xargs perl -pi.bak -e  's/(?<!std::)size_t(?!\w)/std::size_t/g'

Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block.  This is no longer the preferred style.

Run the following shell code:

for c in else endif endforeach endfunction endmacro endwhile; do
    echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed

Ancient CMake versions required upper-case commands. Later command
names became case-insensitive. Now the preferred style is lower-case.

Run the following shell code:

cmake --help-command-list |
grep -v "cmake version" |
while read c; do
    echo 's/\b'"$(echo $c | tr '[:lower:]' '[:upper:]')"'\(\s*\)(/'"$c"'\1(/g'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed

[IO] Replace pointer types with std::vector.

[T] Use Logog formatter pointers. Reduce indent.

[MeL] Remove default NodePartitionedMesh dtor definition.

[MeL] Const correctness of NodePartitionedMesh::isGhostNode().

[IO] Remove default NodePartitionedMeshRead definiton.

[IO] Split long lines.

[IO] Correct doxygen comments.

[IO] Correct private _mpi_comm variable name.

[IO] Correct typo in buildNodeStructTypeMPI() fct name.

[IO] Use NodeData reference instead of pointer.

[IO] Add std namespace identifier for std::getline.

[IO] Remove printMessage().

[IO] Remove unused MPI_status, make message_tag const.

[IO] Add private NodePartitionedMeshReader::readDataFromFile().

This encapsulates MPI IO code.

[MeL] NodePartMesh: Change global node id type to std::size_t.

[IO] Fix some of implicit int type conversions: sign/width.

[IO] Correct doxygen comments.

[IO] Move MPI communicator init to NodePartMeshReader ctor.

[MeL] Use size_t from std namespace.

[IO] Use postfix increment for counters.

[IO] Pass a vector to buildNodeStructType().

[IO] Use std::vector's data() instead of &v[0] in MPI calls.

[IO] Rewrite openASCIIFiles. Scopes and var names.

[IO] Improve const correctness.

[IO] Remove almost unused MeshLib namespace include.

[IO] Improve some comments.

[IO] Add missing includes and remove unused one.

[MeL] Remove unused forward declaration.

[IO] Replace _size_str with on-the-fly conversion.

[IO] Spelling

[IO] Remove duplicate information.

[IO] Improve const-correctness of member fcts.

[IO] Use std::vector in readElementASCII().

[IO] Move up MPI_node deallocation.

[IO] Rename variables.

anode -> node.
s_nodes -> nodes.

_size -> _mpi_comm_size
_rank -> _mpi_rank

[IO] Replace mesh_controls type with std::array.

In the readASCII().

[IO] Variable declaration at definition/use point.

[IO] Rewrite buildNodesStructTypeMPI().

Shorten the code, use MPI blocks for array (of three coordinates).

[IO] Make _mpi_node_type a class variable.

Move initialization to ctor and freeing to dtor.
Function renames.

The reader must exit scope before MPI_FINILIZE
is called.

[IO] Change variable's type long->int; MPI_Send().

[IO] Comment on element types.

[IO] Rename readBinaryDataFromFile(). Change container type.