merged change between nginx 1.6.2 and 1.6.1

hg commit for this pull request:

```
    *) Security: it was possible to reuse SSL sessions in unrelated contexts
       if a shared SSL session cache or the same TLS session ticket key was
       used for multiple "server" blocks (CVE-2014-3616).
       Thanks to Antoine Delignat-Lavaud.
```
See http://hg.nginx.org/nginx/rev/1ee1db30c9b9<br>

```
    *) Bugfix: requests might hang if resolver was used and a DNS server
       returned a malformed response; the bug had appeared in 1.5.8.
```
See http://hg.nginx.org/nginx/rev/20ebe12cfa7a.


```
    *) Bugfix: requests might hang if resolver was used and a timeout
       occurred during a DNS request.
```
See http://hg.nginx.org/nginx/rev/60d2cb03faee.