Implemented updatecss.sh script for background images cache issues fix (#1489047)
* fixed: modsecurity warning: AppDefect: Cache-Control Response Header Missing 'no-store' flag. http://websecuritytool.codeplex.com/wikipage?title=Checks#http-cache-control-header-no-store
Merge pull request #71 from zouguangxian/master

Recommendation Set the cache-control directive to no-cache and no-store.