sprintf: unwanted sign extension
SSL.session: Fixed typo in ECDSA handling.
Runtime: Using FIND_LFUN() with non-LFUNS is an error.

Make sure to fatal if FIND_LFUN() is used with a fake LFUN.
Crypto.ECC: Inhibit module dumping.

This is a workaround for a dumping bug where Crypto.ECC.Curve()->ECDSA
apparently doesn't get encoded properly (the decoded values seems to
not have overloaded Nettle.ECC_Curve()->ECDSA at all).

Should fix ECDSA support in dumped pikes.