add adapter function to wrap http.HandleFunc and http.Handle into a handle

[ducknificient]

while HandlerFunc able to convert default http.HandlerFunc to router, this additional adapter function for better code organizing, example in the router.GET or router.POST can accept http.HandlerFunc.

router.OPTIONS("/*path", httprouter.WrapF(controller.DoOPTIONS))
router.GET("/example/get", httprouter.WrapF(controller.DoGET))
router.POST("/example/post",httprouter.WrapF(controller.DoPOST))

thanks, best regards

[themavik]

WrapF / WrapH adapters map http.HandlerFunc / http.Handler into Handle without extra boilerplate. nit: the WrapH godoc line still says WrapF—rename that comment to match the symbol.