moving http-date from unix to global. (#481)
moving http-date from unix to global. (#481)

utdemir/wai,erikd/wai,frontrowed/wai,tolysz/wai,kazu-yamamoto/wai,sordina/wai,tolysz/wai,frontrowed/wai,utdemir/wai,frontrowed/wai,kazu-yamamoto/wai,erikd/wai,yesodweb/wai,tolysz/wai,sordina/wai,utdemir/wai,creichert/wai,yesodweb/wai,sordina/wai,utdemir/wai,erikd/wai,creichert/wai,tolysz/wai,sordina/wai,frontrowed/wai,erikd/wai