Changes with nginx 0.8.46 19 Jul 2010

    *) Change: now the "proxy_no_cache", "fastcgi_no_cache",
       "uwsgi_no_cache", and "sÓgi_no_cache" directives affect on a cached
       response saving only.

    *) Feature: the "proxy_cache_bypass", "fastcgi_cache_bypass",
       "uwsgi_cache_bypass", and "sÓgi_cache_bypass" directives.

    *) Bugfix: nginx did not free memory in cache keys zones if there was
       an error during working with backend: the memory was freed only
       after inactivity time or on memory low condition.