Fix string length with ifort.

It doesn't like actual arguments that are shorter than the dummy
argument.
Fix typo in mesher dependencies.
Remove constants module from solver list.

Make clean in the specfem3d directory would incorrectly remove the
module, but not the object. Consequently, it would not be rebuilt.
Add arguments to ADIOS stubs.

This causes unused variable warnings, but because of ifort's
-gen-interfaces, the number of arguments needs to be the same for both
the real functions and the stubs.
Swap order of mpi and constants usage.

This would break the replace_use_mpi_with_include_mpif_dot_h.pl script.
Remove dimitrize_args subroutine.

It unfortunately does not work with ifort and -gen-interfaces.
Add a module to hide unused variables.

It's fortunate the Fortran compilers don't seem to check for dead code.
Add dependencies to constants module in solver.
Fix ifort 13 bug with constants module.

Switch from constants module back to constants header in MPI code. It
seems that ifort 13 has a bug when parsing this file with so many uses
of the constants module. ifort 12 and ifort 14 do not exhibit this bug.
Also silence unused variables in serial code.