Testing Mesh::Redistribute() in chessboard fashion

This test is located in tests/pmesh_test000

###Brief

Mesh::Redistribute() should correctly redistribute cells from one process to another.

##Description

Test loads included 3x3x3 rectangular serial mesh (3x3x3.vtk) on one node. GlobalID is computed for cells. Cells are distributed in chessboard fashion and several redistribution steps are performed to shift each cell from each process to another.

If only two processes are used, we assume that chessboard-like partition with one layer of ghost cells will cover the whole mesh. This check is also performed in this test.

##Arguments

The test have one optional parameter, the name of file to load initial mesh from.

One can generate simple IxJxK grids using example/GridGen code.

##CMake tests

If USE_MPI is activated and CMake have variable ${MPIEXEC} set up correctly then the test will seed pmesh_test000_parallel_np_* tests for np=2,3,4 with included 3x3x3.vtk grid.