Spiffy refactoring of utils.py to complement the recent refactor by @nwinklareth 

- Reduced all the line lengths in utils.py to underneath around 76 characters, as per PEP8.
- Re-ordered the functions in utils.py closer to the order they're used.
- Also separated the new InmateDetails class--plus, importantly all of the logic for actually fetching URLs, into its own file, inmate_details.py