- hide the EC_KEY structure definition in ec_lcl.c + add
some functions to use/access the EC_KEY fields
- change the way how method specific data (ecdsa/ecdh) is
attached to a EC_KEY
- add ECDSA_sign_ex and ECDSA_do_sign_ex functions with
additional parameters for pre-computed values
- rebuild libeay.num from 0.9.7
exit() in whatever way works for the intended platform, and define
OPENSSL_EXIT() to have the old meaning (the name is of course because
it's only used in the openssl program)
