Make typings compatible with @types/node.

Fixes name clashes and uses Node-compatible typings where possible.

Changes:
 - setTimout et al now return NodeJS.Timer instead of number
 - No "console" module anymore. Everyone uses it through global.console
 anyway.
 - We have a typed "global" instance with exposed properties now. Any
 "freeform" accesses must go through a `(<any>global).blah` cast.
 - remove tns-core-modules.{base,es6,es2015}.d.ts. Those were needed
 as workarounds for the ES6/DOM/Node type clashes.

apps/app/css-perf-test/root.ts

@@ -1,7 +1,7 @@
 import {Page} from "ui/page";
 
 export function onTap(args: any) {
-    global.startTime = global.time();
+    (<any>global).startTime = (<any>global).time();
     let page = <Page>args.object.page;
     page.frame.navigate("css-perf-test/main-page");
-}
+}