View::share support

In Laravel, you can use View::share(key,value) to share variables to all the views. (http://laravel.com/docs/4.2/responses#views).

When I was using TwigBridge with Laravel 4.1 in my current project, It worked as I expected. Even when I used an include in Twig such as:

 {{ include(
     'partials.sidebar',
     {
         'var' : 'value'
     },                                 
     with_context = false
 ) }}

The View::share variables were available in the partials.sidebar template. Only View::make('template')->with(key,value) variables were subject to the with_context option.

After upgrading to Laravel 4.2 this was no longer true. View::share variables stopped being available in the included view.

This pull requests addresses this issue. I suggest using the Twig addGlobal (http://twig.sensiolabs.org/doc/advanced.html#globals) support which makes the global variables available everywhere.

I'll appreciate feedback about this issue and my suggested implementation.

Best regards,
Bruno S.