Move compression, point2oct and oct2point functions into separate files.

Add a flags field to EC_METHOD.

Add a flag EC_FLAGS_DEFAULT_OCT to use the default compession and oct
functions (all existing methods do this). This removes dependencies from
EC_METHOD while keeping original functionality.

NIST PKV tests.

seed to: this doesn't introduce any binary compatibility issues as the
function is only used internally.

The seed output is needed for FIPS 140-2 algorithm testing: the functionality
used to be in DSA_generate_parameters_ex() but was removed in OpenSSL 1.0.0

- 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

("perl util/ck_errf.pl */*.c */*/*.c" still reports many more.)

PR: 511
Submitted by: Eric Cronin

I've covered all the memset()s I felt safe modifying, but may have missed some.

Additional changes:
 - use EC_GROUP_get_degree() in apps/req.c
 - add ECDSA and ECDH to apps/speed.c
 - adds support for EC curves over binary fields to ECDSA
 - new function EC_KEY_up_ref() in crypto/ec/ec_key.c
 - reorganize crypto/ecdsa/ecdsatest.c
 - add engine support for ECDH
 - fix a few bugs in ECDSA engine support

Submitted by: Douglas Stebila <douglas.stebila@sun.com>

Submitted by: Nils Larsch