[Patch, fortran] Implement inquire(iolength= ) for DTIO

[Dominique d'Humières]

Dear Jerry,

> The new test fails unless I replace 64 with 16 in 'if (rl.ne.64) call abort’. This seems consistent with your comment

I have not been clear enough: I have to replace 64 with 16 even with your patch.

Dominique