Some functions for general file and data accessing and plotting

I'm not entirely sure about how to approach file naming and what stuff should be in each file, but these are the functions I've written so far.  They're all tab spaced and I can work on that if that is a problem.  I haven't been able to figure out how to keep datafilesets.py from following everything else yet.  It isn't really entirely functional yet and I'm not sure if it would be a useful class since my perspective on the data we're analyzing has changed.  These aren't the functions requested yet.