Remove testing for version 0.8 of Node.
Shorten test times.
Reenable garbage-signature.vtt.
Implement new text position alignment setting.
Fix style of position setting call.
Update README for NodeVTT and test suite changes.
Update text from andreasgal to Mozilla

There are old text that was andreasgal and we are now moved to Mozilla
and we need to change it to reflect the new repo.
Implement new line alignment setting.