Expose phpdesktop object to javascript and GetVersion() method

[GoogleCodeExporter]

We need to expose some API to javascript, a "phpdesktop" object should be 
attached to javascript window object.

In PHP the version info can be accessed through $_ENV["PHPDESKTOP_VERSION"].

Original issue reported on code.google.com by czarek.t...@gmail.com on 23 Jan 2014 at 9:47