support mitigating BEAST attack

According to http://redmine.lighttpd.net/projects/lighttpd/wiki/Release-1_4_30

"...by setting

ssl.cipher-list = "ECDHE-RSA-AES256-SHA384:AES256-SHA256:RC4-SHA:RC4:HIGH:!MD5:!aNULL:!EDH:!AESGCM"

you can mitigate BEAST attacks."
Merge pull request #683 from dhatz/RELENG_2_1

support mitigating BEAST attack, see http://forum.pfsense.org/index.php/topic,63001.0.html