Updated grunt declarations to match 0.4.x documentation.

Had to weaken some return types for TypeScript (left comments).

Conflicts:
	gruntjs/gruntjs.d.ts

gruntjs/gruntjs-tests.ts

@@ -4,7 +4,7 @@
 // http://gruntjs.com/getting-started#an-example-gruntfile
 
 // exports should work same as module.exports 
-exports = function (grunt) {
+exports = (grunt: IGrunt) => {
 
     // Project configuration.
     grunt.initConfig({