Add async calls to normal JavaScript

Currently async call are only available with -gen js if you unwire the client send/recv methods (pretty messy and unintuitive) or if you use jQuery (-gen js:jquery). This patch makes it easy to use async callbacks with any Thrift call by simply appending the desired callback to the args). e.g.

client.myFunc(arg1, arg2, function (result) {
//do callback stuff with result
//result will be the normal return value or the exception
});

This patch preserves the existing sync call style (just leave off the callback).

Compiler js generator changes
=============================

• Combining node and jquery switches now results in a compile error rather than silently producing corrupt code in ./gen-nodejs
• Updated comments
• Added ability to make async calls without jQuery

Node test client.js
===================

• Corrected comments and spelling

JS thrift.js
====================

• Added support for async calls w/o jQuery

Node/JS test.js
====================

• Updated comments to clarify jQuery dependency (-gen js:jquery)

Node/JS test-nojq.js test-nojq.html
===================================

• Full test suite for normal JS build (-gen js)

Node http test server and handler
=================================
linted