Changes for CryptX

TODO:
        - RSA|DSA|ECC: verify_key($level) (basic check + extented primality test)
        - better primality testing: http://questhub.io/realm/perl/quest/519032ee1088c76505000035
        - DSA: generate_key($p, $q, $g), generate_key(\$dsa_params_der), generate_key($dsa_params_file)
        - DH: generate_key($base, $prime), generate_key(\$dh_params_der), generate_key($dh_params_file)
        - DH: key2hash should dump $base and $prime as well (perhasp add base, prime to dh_key struct)
        - investigate - "libtom-src/bn_mp_invmod.c", line 37: warning: statement not reached
        - investigate - solaris crash:
          - http://ppm4.activestate.com/sun4-solaris/5.14/1400/M/MI/MIK/CryptX-0.017.d/log-20130924T103600.txt
          - t/pk_rsa.t crashes after: ok 32 - verify_hash
          - t/pk_dsa.t crashes after: ok 28 - decrypt
        - XS croaks should report the "real caller" (Crypt::Mac::*, Crypt::Mode::*, ...)

0.020   2014/01/18
        - INCOMPATIBLE CHANGE: huge redesign of Crypt::PK::ECC
        - ECC now supports curves y^2 = x^3 + a*x + b
        - ECC you can use custom curves
        - ECC import/export of keys in DER/PEM format now compatible with openssl
        - enabling compile options ASM + ECC_TIMING_RESISTANT
        - added many test vectors (RSA, DSA, EC) for interoperability with openssl

0.019   2013/10/20
        - fixed broken CAMELLIA implementation

0.018   2013/10/18
        - DSA: make_key + sign_hash fixes

0.017   2013/09/24
        - lowering MIME::Base64 version requirement
        - support for import/export of password protected RSA/DSA keys
        - RSA: added - export_key_pem('public_x509')
        - better handling of dh_free/rsa_free/dsa_free/ecc_free
        - added openssl test vectors
        - fixed compiler warnings (RSA/DSA/ECC/DH)

0.016   2013/09/15
        - added missing test for key2hash, sign_hash, verify_hash
        - fixed build failures on VC6

0.015   2013/09/12
        - only documentation fixes

0.014   2013/09/11
        - Crypt::Digest::NNN + Crypt::Mac::NNN - can produce Base64-URL-Safe encoded digest/mac
        - Crypt::PRNG + Crypt::PRNG::NNN - Base64-URL-Safe encoded random bytes (random_bytes_b64u/bytes_b64u)
        - Crypt::PK::RSA/DSA/DH/ECC - sign/verify replaced by sign_message/verify_message + sign_hash/verify_hash
        - Crypt::PK::RSA/DSA/DH/ECC - new method key2hash
        - documentation fixes

0.013   2013/08/28
        - DSA/RSA/ECC/DH - importing keys from string changed - now: $pk->import_key(\$buffer_with_key)
        - DSA/RSA/ECC/DH - size() and is_private() now return undef if no key loaded
        - improved RSA doc

0.012   2013/06/17
        - README, LICENSE etc. to improve CPANTS score
        - somehow works with perl 5.6.2

0.011   2013/06/15
        - fixing various compiler warnings

0.009   2013/05/19
        - doc fixes
        - requires perl 5.8.8 or higher
        - INCOMPATIBILITY: all digest related 'xxx_base64' functions renamed to 'xxx_b64'

0.008   2013/05/02
        - fixed prng test failures
        - Crypt::Digest::* croaks with the "real caller" (not a nice solution)

0.007   2013/04/23
        - Crypt::PRNG supports add_entropy() - without params
        - Crypt::PRNG fork-safe & thread-safe
        - random_string has default $len = 20
        - doc fixes
        - cpan tester failure fix for pk_dsa.t

0.006   2013/04/19
        - added Crypt::KeyDerivation
        - Win64 compatibility

0.005   2013/04/18
        - added Crypt::PRNG::Fortuna|RC4|Sober128|Yarrow
        - added Crypt::PK::RSA|DSA|ECC|DH

0.004   2013/04/16
        - removing illegal Crypt::Random

0.003   2013/04/16
        - added Crypt::Mode::CBC|CFB|CTR|ECB|OFB
        - added Crypt::AuthEnc::CCM|EAX|GCM|OCB

0.002   2013/04/11
        - first release on CPAN