clean up stream resources when websockets completes
clean up stream resources when websockets completes

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