Add a simple example to show how the module system works.

http://code.google.com/p/phantomjs/issues/detail?id=47

examples/module.js

@@ -0,0 +1,4 @@
+var universe = require('./universe');
+universe.start();
+console.log('The answer is', universe.answer);
+phantom.exit();

examples/universe.js

@@ -0,0 +1,8 @@
+// This is to be used by module.js example.
+
+exports.answer = 42;
+
+exports.start = function () {
+    console.log('Starting the universe....');
+}
+