Minor naming issue in DefaultFileGenerator Follow

Probably you have noticed yourselves, but DefaultFileGenerator class definition contains getExtenstion(INodeAdapter) method; that could be confusing for a newcomer.

Also, speaking of submitting issues - what is your policy of using a bugtracker? It seems that you've opened registration at http://www.jetbrains.net/tracker/workspace/mps, but I'm not sure if it would be better to submit such issues directly to tracker or to post them here for your review.