Core: Switch from modules to just window.setTimeout etc.

Using modules for window.setTimeout etc. made those functions cached and
disabled Sinon mocking, making effects tests fail. Just writing
window.setTimeout directly is smaller anyway.

src/var/clearInterval.js

@@ -1,3 +0,0 @@
-define(function() {
-	return window.clearInterval;
-});

src/var/clearTimeout.js

@@ -1,3 +0,0 @@
-define(function() {
-	return window.clearTimeout;
-});

src/var/setInterval.js

@@ -1,3 +0,0 @@
-define(function() {
-	return window.setInterval;
-});

src/var/setTimeout.js

@@ -1,3 +0,0 @@
-define(function() {
-	return window.setTimeout;
-});