MINOR: ssl: add fetchs 'ssl_c_der' and 'ssl_f_der' to return DER formatted certs

ssl_c_der : binary
  Returns the DER formatted certificate presented by the client when the
  incoming connection was made over an SSL/TLS transport layer. When used for
  an ACL, the value(s) to match against can be passed in hexadecimal form.

ssl_f_der : binary
  Returns the DER formatted certificate presented by the frontend when the
  incoming connection was made over an SSL/TLS transport layer. When used for
  an ACL, the value(s) to match against can be passed in hexadecimal form.
(cherry picked from commit 43e7958def282deebde934950b133a1dd9edaabf)
MINOR: ssl: add statement to force some ssl options in global.

Adds global statements 'ssl-default-server-options' and
'ssl-default-bind-options' to force on 'server' and 'bind' lines
some ssl options.

Currently available options are 'no-sslv3', 'no-tlsv10', 'no-tlsv11',
'no-tlsv12', 'force-sslv3', 'force-tlsv10', 'force-tlsv11',
'force-tlsv12', and 'no-tls-tickets'.

Example:
      global
        ssl-default-server-options no-sslv3
        ssl-default-bind-options no-sslv3
(cherry picked from commit 2c86cbf7539af2008d61780b14f37ea8c46c2192)
BUG/MINOR: ssl: correctly initialize ssl ctx for invalid certificates

Bug reported by John Leach: no-sslv3 does not work using some certificates.

It appears that ssl ctx is not updated with configured options if the
CommonName of the certificate's subject is not found.

It applies only on the first cerificate of a configured bind line.

There is no security impact, because only invalid nameless certficates
are concerned.

This fix must be backported to 1.5
(cherry picked from commit 0bed9945eec049f12638ac3ef82e2084ac4da1c0)
[RELEASE] Released version 1.5.7

Released version 1.5.7 with the following main changes :
    - BUG/MEDIUM: regex: fix pcre_study error handling
    - BUG/MINOR: log: fix request flags when keep-alive is enabled
    - MINOR: ssl: add fetchs 'ssl_c_der' and 'ssl_f_der' to return DER formatted certs
    - MINOR: ssl: add statement to force some ssl options in global.
    - BUG/MINOR: ssl: correctly initialize ssl ctx for invalid certificates
    - BUG/MEDIUM: http: don't dump debug headers on MSG_ERROR
    - BUG/MAJOR: cli: explicitly call cli_release_handler() upon error
    - BUG/MEDIUM: tcp: fix outgoing polling based on proxy protocol
    - BUG/MEDIUM: tcp: don't use SO_ORIGINAL_DST on non-AF_INET sockets