Modified double precision to 15 decimal places for compatibility with LAPACK.
Switched method for timestamp in params.f90 to use the FORTRAN intrinsic
subroutine 'DATE_AND_TIME' for intel/gnu portability.

Added check_file subroutine in params.f90 to replace multiple INQUIRE
statements.

Added checking if input files exist in rho_prop.f90 using check_file
subroutine.
Replaced GNU intrinsics REALPART and IMAGPART with FORTRAN intrinsics REAL and
AIMAG fields.f90 for intel/gnu portability.
	modified:   src/fields.f90