Use a custom comparator for ID numbers and DOBs

[mbauman]

In dedupe's logs, it reports:

INFO:dedupe.index:Removing stop word 47
INFO:dedupe.index:Removing stop word 9-
INFO:dedupe.index:Removing stop word 25

We're using String comparisons for both SSN and DOB — it shouldn't be removing any aspect of either as a stop word.

[potash]

I once asked about this: dedupeio/dedupe-examples#39

[mbauman]

Ah, interesting. Do you think this is beneficial? I've been trying to understand their comparator plugin architecture to setup custom comparisons, and then we could fine-tune this behavior for dates and SSNs… if it's useful at all.