Added nest type for using nested model parameters. Reorganized things to have debug level 1 only write to screen; 2 to files.

Added integer 'matnum' (material number) to osolve. Added logical 'nest' to parameters. Cleaned up a bit.

Reverted to using 'include mpif.h' as the use of mpi.mod requires the MPI module be compiled with the same compiler as the DOUAR source, which is not true on geodyncomp