20141104__az__general__maricopa__precinct.csv should have separate party and candidate

[warwickmm]

2014/20141104__az__general__maricopa__precinct.csv appears to include the party and candidate names in a single column.

For example, the first 4 column headers are

precinct_name,choice_name,party_id,candidate_id

However, line 6 of the file contains the following as the first 4 columns

0001 ACACIA,"REP - SCHWEIKERT, DAVID",,1

It seems that the party name and candidate name are grouped into the choice_name column, while party_id is blank, and candidate_id is an integer. It would be nice if we can extract the party and candidate names from the choice_name column to create party and candidate columns to be consistent with the other data files.