Tons of changes

Fixes #3

- pep8
- factor out common code
- clean up
- make it possible to continue comment/submission retrivial in the event of a failure (append instead of overwrite)
- add exception handling
- store content as utf-8
- rerun comment and submission removal until everything is gone
- just login if new account already exists
- double check password during new account creation
- use format() instead of '%'