Erik. Implemented CGNSWriter class. Slight changes.

1) Added CGNSWriter class for output purposes
2) Implemented WriteGridToFile routine that writes grid structure and connectivity to CGNS database (periodic not suported yet)
3) Parallel helper improved. Added MPI_Gather and MPI_Gatherv aliases.
4) Gengrid2D bug fix.
5) Added SaveGrid routine to kernel
Erik. Reading and saving grid works!

1) Gengrid2D parallelized.
2) CGNSReader finished. Several bug fixes and mesh generation made parallel.
3) Several wrappers for MPI routines
4) Added WriteField routine that writes variable field to cgns database.
5) Logger now logs in separate files and parallel. Rethink of logic.
Erik. Many bug fixes. Need of further cleaning of debug output

1) Fixed parallel reading and writing bugs for cgns i\o
2) Partitioning works fine