Added system test for sticky options.
Added system test for sticky options.

wanrui/ngx_pagespeed,pagespeed/ngx_pagespeed,0x0mar/ngx_pagespeed,digideskio/ngx_pagespeed,0x0mar/ngx_pagespeed,pagespeed/ngx_pagespeed,wanrui/ngx_pagespeed,digideskio/ngx_pagespeed