Record past Roth contributions in input

[wscott]

The idea of this tool is that you rerun in every year with updated balances to plan what to do each year. So it plans 30 years in the future, but you only use the first year of the plan. But currently, if we do a Roth conversion we can't record that in the input so that future runs of this tool will know when that contribution is available to spend.

My plan is to have something like this in the input:

[roth]
bal = 100000    # current balance
contrib = [[ 45, 20000],   # previous contributions in [age, ammount] pairs
           [ 46, 10000],
           [ 47, 10000]]

Then the tool would know that contributions can be spent 5 years after they are added before age 59.5.

But the syntax seems a bit awkward.