Feature [#44907875] Display weeks as dates

Instead of displaying W1/W2.../W5, users can display the abbreviated
dates for the associated starting Monday.
Feature [#44907875] Removes debugging statement

On successful preferences save, don't console.log the returned resource.
Form tweaks, migration tweak. This didn't really work so much without pre-populating the user_preferences associations for users. Initialize a user_preferences association, too, when creating users.
Merge pull request #92 from rescuedcode/add_user_pref_display_weeks_as_dates

Feature [#44907875] Display weeks as dates
schema.rb