Pull Request for Issue954:  Sample Management and Fast Scan Memory Leak Issues

Hey @dretrex , I think that I'm done cleaning up things for now.

I didn't manage to get all (or even most) of the QVector stuff, but I did make a lot of progress on memory leaks in general. I hate to say it, but it warrants going over with a fine toothed comb ... I could have made bad changes by being to focused on fixing the problem without looking at the larger context.

Could you check over the QVector stuff that I did? I'm not too confident about it (so much so that I left the old code commented out in every case). If you feel real confident in the changes and feel like doing it you can remove the commented out code.