Deservicify core (#2458)

* De-servicify router (mostly)

Still uses the redraw service, but it no longer has an intermediate
service of its own.

Also, did a *lot* of test deduplication in this. About 30-40% of the
router service tests were already tested on the main router API instance
itself.

Bundle size decreased from 9560 to 9548 bytes min+gzip.

* Merge `m.mount` + `m.redraw`, update router

Simplifies the router and redraw mechanism, and makes it much easier to
keep predictable.

Bundle size down to 9433 bytes min+gzip, docs updated accordingly.

* Make `mithril/render` just return the `m.render` function directly.

* Deservicify `m.render`, revise `m.route`

- You now have to use `mithril/render/render` directly if you want an
  implicit redraw function. (This will likely be going away in v3.)
- Revise `m.route` to only `key` components

* Add `redraw` to `m.render`, deservicify requests

* Test error logging

* Update docs + changelog [skip ci]

request/request.js

@@ -2,9 +2,8 @@
 
 var buildPathname = require("../pathname/build")
 
-module.exports = function($window, Promise) {
+module.exports = function($window, Promise, oncompletion) {
 	var callbackCount = 0
-	var oncompletion
 
 	function PromiseProxy(executor) {
 		return new Promise(executor)
@@ -191,8 +190,5 @@ module.exports = function($window, Promise) {
 				encodeURIComponent(callbackName)
 			$window.document.documentElement.appendChild(script)
 		}),
-		setCompletionCallback: function(callback) {
-			oncompletion = callback
-		},
 	}
 }

request/tests/test-jsonp.js

@@ -3,17 +3,15 @@
 var o = require("../../ospec/ospec")
 var xhrMock = require("../../test-utils/xhrMock")
 var Request = require("../../request/request")
-var Promise = require("../../promise/promise")
+var PromisePolyfill = require("../../promise/promise")
 var parseQueryString = require("../../querystring/parse")
 
 o.spec("jsonp", function() {
 	var mock, jsonp, complete
 	o.beforeEach(function() {
 		mock = xhrMock()
-		var requestService = Request(mock, Promise)
-		jsonp = requestService.jsonp
 		complete = o.spy()
-		requestService.setCompletionCallback(complete)
+		jsonp = Request(mock, PromisePolyfill, complete).jsonp
 	})
 
 	o("works", function(done) {

request/tests/test-request.js

@@ -10,10 +10,8 @@ o.spec("request", function() {
 	var mock, request, complete
 	o.beforeEach(function() {
 		mock = xhrMock()
-		var requestService = Request(mock, PromisePolyfill)
-		request = requestService.request
 		complete = o.spy()
-		requestService.setCompletionCallback(complete)
+		request = Request(mock, PromisePolyfill, complete).request
 	})
 
 	o.spec("success", function() {
@@ -835,10 +833,7 @@ o.spec("request", function() {
 			// if you use the polyfill, as it's based on `setImmediate` (falling
 			// back to `setTimeout`), and promise microtasks are run at higher
 			// priority than either of those.
-			var requestService = Request(mock, Promise)
-			request = requestService.request
-			complete = o.spy()
-			requestService.setCompletionCallback(complete)
+			request = Request(mock, Promise, complete).request
 			mock.$defineRoutes({
 				"GET /item": function() {
 					return {status: 200, responseText: "[]"}