Revision 193

In procedure cv30_unsat, in downdraft_loop, there was a test on
any(inb >= i .and. lwork). It was useless to do this test at each
iteration since, if it becomes true for a given value of i, it is
necessarily true for all subsequent (lower) values of i. So instead,
we compute imax before the loop.

In procedure cv30_unsat, no need to initialize wdtrain to 0 because it
is computed inside the loop at all positions where it will be useful.