Rewrite of analysis script.

Analysis.py changed to:
0. Be useful and re-usable 
1. Use raw sead plug data (rather than data trimmed by another script)
2. Write spectrum to file or stdout
3. Produce plots and display them or write to disk
4. Produce mean normalized power spectra for current signal, as opposed to frequency distributions

This is intended to be a utility that any of us can use to do analysis. I've also intended this to be easily readable, and easily taken apart and repurposed. Check it out the guide by calling:
$ python Analysis.py -h