Update from 1.5.5 to 1.5.6.
*) Feature: the "fastcgi_buffering" directive.
*) Feature: the "proxy_ssl_protocols" and "proxy_ssl_ciphers"
Thanks to Piotr Sikora.
*) Feature: optimization of SSL handshakes when using long certificate
*) Feature: the mail proxy supports SMTP pipelining.
*) Bugfix: in the ngx_http_auth_basic_module when using "$apr1$"
password encryption method.
Thanks to Markus Linnala.
*) Bugfix: in MacOSX, Cygwin, and nginx/Windows incorrect location might
be used to process a request if locations were given using characters
in different cases.
*) Bugfix: automatic redirect with appended trailing slash for proxied
locations might not work.
*) Bugfix: in the mail proxy server.
*) Bugfix: in the ngx_http_spdy_module.