Support for the "global" namespace

[fabpot]

The following construct is valid but not supported by PHP-Parser:

namespace {
    echo 'Hello';
}

Here is the error:

PHP Catchable fatal error:  Argument 1 passed to PHPParser_PrettyPrinterAbstract::p() must be an instance of PHPParser_NodeAbstract, array given, called in lib/PHPParser/PrettyPrinterAbstract.php on line 105 and defined in lib/PHPParser/PrettyPrinterAbstract.php on line 127

[nikic]

The parser did support this, but the pretty printer failed to print it. Fixed in fb45e8a.