Add habits migration + interface tweaks

(didn't use rebase --interactive correctly, so I don't remember)

(didn't use rebase --interactive correctly, so I don't remember)

(didn't use rebase --interactive correctly, so I don't remember)

(didn't use rebase --interactive correctly, so I don't remember)

(didn't use rebase --interactive correctly, so I don't remember)

(didn't use rebase --interactive correctly, so I don't remember)
Created model HabitInstance and added routes

Misc fixes: send sign-up conf email, let new user add habits, tweak auth user's root path & misc habit fixes if no schedule is defined

Add schema comments to each model

Added habit model methods to create next instance, and cleaned up before_save code
Added Habit#create_instances to generate new HabitInstances

Added whenever gem and scheduled Habit.create_instances to run at 12:01am CST

Add secret_token.rb to gitignore file

Remove secret_token.rb from tracking
Add token to Habit_instances model & generate during before_save

Add token to Habit_instances model

Added completion token to habit_instance, with controller method & route
Added site-wide footer showing development history

Fixed my bashrc & profile, so updated scheduler.rb to not use interactive login bash for script runner

Just kidding - I do still need the -l in schedule so bash runs a login shell
Added user_id to HabitInstance model & populated the column

Forgot to include db/schema.rb in previous commit

Changed styling on lists so devlog didn't look weird

Added tmp symlink to gitignore; moved tmp dir to resolve NAS/NFS permissions issues
Added ability to generate reminder emails, with a simple reminder email layout

Scheduled email reminder job to run every 5 minutes
Lots of little UI tweaks: Show habit details, links to edit user & habits, reformat timestamps, make user/habit settings displays look pretty[ier]. And fixed some bugs of stuff I broke along the way
Adds Habit model, HabitInstance, InstanceMailer -- all the fundamental underlying functionality necessary to be basically operational.