Support scope 'embedding.*'

[Timandes]

When I run command 'fold_all' at the beginning of a PHP file, I found that the scope there is embedding.php, not source.php.

The PHP file mentioned may be like:

<?php
/* {{{ PHP Info */
phpinfo();
/* }}} */

So the config below will not work:

        {
            "endMarker": "}}}",
            "scope": "source.php, source.c",
            "startMarker": "{{{"
        }

, even if I add 'embedding.php' to the scope list above.

Therefor I commited this patch in order to solve this kind of issue.