added party and precinct_split_electoral_district / ballot_style into the schema and processor.
Merge branch 'v5.0_update' of https://github.com/votinginfoproject/Metis into v5.0_update
added the new constraints so the rules engine will check the new elements that were added in v5.0
removed convertId function from basemapper because mongoose was converting anyway. added gis_xy to simpleaddress schema / mapper