Upstream: only call peer.free() if peer.get() selected a peer.


git-svn-id: svn://svn.nginx.org/nginx/trunk@5133 73f98a42-aea0-e011-b76d-00259023448c
Upstream: removed double-free workarounds in peer.free() methods.


git-svn-id: svn://svn.nginx.org/nginx/trunk@5134 73f98a42-aea0-e011-b76d-00259023448c
Mail: IPv6 backends (ticket #323).


git-svn-id: svn://svn.nginx.org/nginx/trunk@5135 73f98a42-aea0-e011-b76d-00259023448c
Upstream: removed sorting of upstream servers.

Sorting of upstream servers by their weights is not required by
current balancing algorithms.

This will likely change mapping to backends served by ip_hash
weighted upstreams.


git-svn-id: svn://svn.nginx.org/nginx/trunk@5136 73f98a42-aea0-e011-b76d-00259023448c
Upstream: removed rudiments of upstream connection caching.

This functionality is now provided by ngx_http_upstream_keepalive_module.


git-svn-id: svn://svn.nginx.org/nginx/trunk@5137 73f98a42-aea0-e011-b76d-00259023448c