The dependency on jquery could be removed in examples/chat-client.html

[widged]

As I played with the examples, I made changes to the js code in examples/chat-client.html. https://github.com/widged/WebSockets.jl/blob/master/examples/chat-client.html.
Let me know if this is of any interest to you and whether you are ok with es6 or prefer strict es5.

[hustf]

Pull request welcome!
IE11 people, if this does not work, can use the old versions.
And it is good to get rid of the dependency.

[widged]

Done. Do not hesitate to let me know if you need more information.

[hustf]

Before this pull request, Firefox indicated:

Using //@ to indicate sourceMappingURL pragmas is deprecated. Use //# instead
[Learn More]
jquery-1.9.1.min.js:1
Use of getPreventDefault() is deprecated.  Use defaultPrevented instead.
jquery.js:68

[hustf]

Part of tagged release 0.5.