Stop using `methods` to generate methods

[blakeembrey]

For the next major I think we should consider removing the autogenerated methods from here:

router/index.js

Lines 436 to 443 in 36ae18f

	// create Router#VERB functions
	methods.concat('all').forEach(function (method) {
	Router.prototype[method] = function (path) {
	const route = this.route(path)
	route[method].apply(route, slice.call(arguments, 1))
	return this
	}
	})

.

We can provide the main ones statically, and instead rely on a new router.method("METHOD", ...) for the obscure ones. The main reason is to avoid confusion arounds methods such as BIND, which overwrote the JavaScript .bind property, which created a number of bug reports in Express 4.

[jonkoops]

Perhaps we should set up a milestone for the next major so we can keep track of all the issue that should go into it?