Using bracket syntax, highlighting fails for global namespace

[joshvarner]

The bundle currently relies on there being a namespace name after the namespace keyword, but it needs to be able to support the following syntax, which is used for defining items to be placed in the global namespace.

<?php

namespace {
    // This function will go into the global namespace as `\foo()`
    function foo() {
        echo "Bar!";
    }
}

namespace blah {
    // This function will go into the `blah` namespace as `\blah\foo()`
    function foo() {
        echo "Bar!";
    }
}

?>