Multiple security and bug fixes.
    
    - fix CVE-2014-3570 - incorrect computation in BN_sqr()
    - fix CVE-2014-3571 - possible crash in dtls1_get_record()
    - fix CVE-2014-3572 - possible downgrade of ECDH ciphersuite to non-PFS state
    - fix CVE-2014-8275 - various certificate fingerprint issues
    - fix CVE-2015-0204 - remove support for RSA ephemeral keys for non-export
      ciphersuites and on server
    - fix CVE-2015-0205 - do not allow unauthenticated client DH certificate
    - fix CVE-2015-0206 - possible memory leak when buffering DTLS records
    - add ECC TLS extensions to DTLS (#1119803)
    - do not send ECC ciphersuites in SSLv2 client hello (#1090955)
    - copy digest algorithm when handling SNI context switch