Testing Partitioner class and computing number of connected components

This test is located in tests/pmesh_test001

###Brief

Initial mesh is partitioned using one of available partitioner. Then the number of cell elements and connected components is computed.

##Description

Test loads one of provided serial or distributed meshes. Different partitioner may be used to (re)partition the mesh. Simple statistics is computed: number of cells, number of connected components.

##Arguments

The test have two required parameters and one optional.

First parameter is the input mesh file.

The second parameter is the desired partitioner:

0 - Inner_RCM
1 - Parmetis
2 - Zoltan_HSFC
3 - Zoltan_RIB
4 - Zoltan_RCB
5 - Zoltan_PHG
6 - Zoltan_Scotch
7 - Zoltan_Parmetis
-1 - No partitioner

Optional second parameter is used to define ParMETIS action (default: 0):

0 - Partition
1 - Repartition
2 - Refine

##CMake tests

If USE_MPI is activated and CMake have variable ${MPIEXEC} set up correctly then the test will seed pmesh_test001_np tests for available partitioners and np=2,4 with included Menger Sponge 9x9x9 mesh.