ectab.in: Add previously unacceptable curves from X9.62.

ectab.in: Add previously unacceptable curves from X9.62.

Previously we rejected curves with large cofactors.  We've now
recognized that this was unnecessary.  This change includes the curves
from X9.62 which were previously omitted for having large cofactors.

The curve c2onb239v2 seems incorrect as specified.  In particular, the
specified base point G isn't in the prime-order subgroup -- in fact, it
seems as if the curve group E is cyclic and G is primitive in E.  The
base point included in the table is actually P = 6 G, which does
correctly generate the prime-order subgroup.