fix isNewline cannot be read from php 5.3

php 5.3 cannot access protected properties in closure thats why i get here:

```
PHP Fatal error:  Cannot access protected property Webcreate\Conveyor\Subscriber\BuilderSubscriber::$needsNewline in phar:///usr/local/sbin/conveyor.phar/src/Webcreate/Conveyor/Subscriber/BuilderSubscriber.php on line 72
```
You probably want a test for that, can you help me where to start?