Changing vcluster initialization

CHANGELOG.md

build_pdata.sh

example/Grid/0_simple/main.cpp

example/Grid/1_stencil/main.cpp

example/Vector/0_simple/main.cpp

example/Vector/1_celllist/main.cpp

example/Vector/1_verlet/main.cpp

images/CartDecomposition_gen_vtk.cpp

images/vector.cpp

openfpm_io

openfpm_numerics

openfpm_vcluster

src/Decomposition/CartDecomposition_unit_test.hpp

src/Decomposition/Distribution/Distribution_unit_tests.hpp

src/Decomposition/Distribution/metis_util_unit_test.hpp

src/Decomposition/ORB.hpp

src/Decomposition/ORB_unit_test.hpp

src/Graph/DistGraphFactory.hpp

src/Graph/dist_map_graph.hpp

src/Graph/dist_map_graph_unit_test.hpp