Some changes

Unfortunately I didn't do my commits properly so you can't view differences in the Files Changed tab easily. Mostly README.md edits for WoS documentation, edited docstrings in tethne.py, restructured folders in project to support Python packaging, and made very minor substantive changes to tethne.py. Next I will be stripping out the functions of tethne.py into their own modules to make them more reusable.