refactoring sanitizeHeaderValue.
refactoring sanitizeHeaderValue.

dylex/wai,frontrowed/wai,rgrinberg/wai,sordina/wai,awpr/wai,tolysz/wai,creichert/wai,utdemir/wai,urbanslug/wai,erikd/wai,frontrowed/wai,coypoop/wai,yesodweb/wai,kazu-yamamoto/wai,awpr/wai,creichert/wai,coypoop/wai,frontrowed/wai,dylex/wai,awpr/wai,sordina/wai,tolysz/wai,erikd/wai,soenkehahn/wai,awpr/wai,tolysz/wai,urbanslug/wai,urbanslug/wai,utdemir/wai,rgrinberg/wai,rgrinberg/wai,sordina/wai,rgrinberg/wai,erikd/wai,dylex/wai,sordina/wai,erikd/wai,frontrowed/wai,soenkehahn/wai,soenkehahn/wai,dylex/wai,utdemir/wai,tolysz/wai,yesodweb/wai,rgrinberg/wai,kazu-yamamoto/wai,utdemir/wai,coypoop/wai,soenkehahn/wai,coypoop/wai,urbanslug/wai