Update sfmakedepend from upstream.

See
https://github.com/kshedstrom/roms/ (sfmakedepend is under
ROMS/bin/sfmakedepend).  Only the copyright notice has changed.
Generate fortran dependencies by module name.

gfortran doesn't update the .mod files if their contents haven't changed
(possibly other compilers do the same).  By having object files depend
upon the .mod files rather than other object files, cascade compilation
is trivially avoided if such a compiler is being used, making
recompilation frequently much faster.