Add segment-literal notation for expressions

[JustBlackBird]

I've added support for segment-literal notation for variables names as in Handlebars.js. In other words one can use value.[some key] syntax.

For example:

$engine = new \Handlebars\Handlebars();

echo $engine->render(
    '{{greetings.[hello world!]}}',
    array(
        'greetings' => array(
            "hello world!" => 'Hello from Handlebars'
        )
    )
);

The tests for such feature in handlebars.js are available here: http://jsfiddle.net/L7LWM/1/

[everplays]

thanks.

[JustBlackBird]

You are welcome

[wwwsevolod]

oh it is cool, waiting for subexpressions (if i've found free time, ill implement it myself)