atoms.f: changed the internal documentation.
atoms.f: removed static atom array allocation.
atoms.f: changed position of the save statement to be at the end.
parallelparams.f: added an MPI derived datatype for the atomtype f90 construct.
Makefile: added dependencies for readxyz.o of parallelparams.o and atoms.o for paralleparams.o.
getxyz.f: changed so that only process 0 gets information about the coord file to read.
Makefile: noted getxyz.o requires parallelparams.o.
fatal.f: calls MPI_Abort on termination.