Updates and basic functionality
Added subject model, new views and db load

Subject -> Category -> Question hierarchy.
Load reads a spreadsheet and builds categories and questions in the
database (needs work).
Add subject, fix broken commits
Minor updates
Added templates, menus and rudimentary css.
Fixed load.py, loaded database
Set up css throughout, some cleanup
Home link and review mode

Site name is now a link.
Question list pages allow for answers to be shown or hidden.
Updates to notes and css to clean things up a bit.
Merge branch 'dev'