First commit of WA loader. Needs refactor.

Initial commit of Washington's loader. Obviously needs some refactoring, but am sending this for Geoff to look over.

In order of most importance, these are the issues with the loader:

- Normalize column headers (e.g. county A might use "candidate_name" while county B might use "CANDIDATE_FULL_NAME")

With regards to normalizing the headers, I was thinking of creating a class to test the headers beforehand and select the column the most closely matches what we want.

- Add in .xls(x) support.

This isn't too difficult, but there are so many weird things with this loader that I wanted somebody to look it over before I added a class to parse the .xls(x)

- Fix memory issues on larger files. 

Some multimillion line files eat up most of my 8GB of RAM, as well as taking ages to computer. This is *way* too long.