UI:
    * use key_dates to highlight when I quit, when we own car

For bills:
    [DONE] * calc quit date based on finance data
    [DONE] * calc date of car lease end or buyout
    * use this to populate bill estimates, so this allows totals / year and simplifies calc.py

    * might need to be able to mark a specific bill as an outlier:
        - so we ignore the data somehow (think Gas is messing with my bills)
        - and even electricity, water, etc. for when we were away in Europe but mostly gas/elec
