exit_all not in a module #1142

At some point the exit logic from utilities should be revisited.
This pull request is skirting around the issue to only deal with fixsystem.

DART/assimilation_code/modules/utilities/utilities_mod.f90

Lines 89 to 99 in 890a3be

	! this routine is either in the null_mpi_utilities_mod.f90, or in
	! the mpi_utilities_mod.f90 file, but it is not a module subroutine.
	! the mpi files use this module, and you cannot have circular module
	! references. the point of this call is that in the mpi multi-task
	! case, you want to call MPI_Abort() to kill the other tasks associated
	! with this job when you exit. in the non-mpi case, it just calls exit.
	interface
	subroutine exit_all(exitval)
	integer, intent(in) :: exitval
	end subroutine exit_all
	end interface

Originally posted by @hkershaw-brown in #1121

The logic of utilities and mpi utilities and the orphan exit_all subroutine is not great.