Update 2000/2004/2008/2012 results datasets with Alaska county-level results

[scottcame]

Currently, our 2000-2008 presidential election results datasets have data for Alaska at the State House district level, not the county level like all other states. To get to the "county" level (which in Alaska means Boroughs for part of the state, and Census Areas for the unincorporated part), we need to OCR the precinct-level results PDFs for each House District, assemble those into a text file, then write some code to merge the precinct code with the AlaskaPrecinctBoroughMapping.csv dataset on DW.

The 2012 election results dataset does not yet include data for Alaska, so we need to do a similar exercise for that dataset.

Results PDFs are available on the Alaska state website, here: http://www.elections.alaska.gov/Core/voterregistrationstatistics.php

If you begin working on this issue, please drop a post on the #election-transparency channel in Slack to let everyone know.