Republished edited v5.0 Schema as vip_spec.xsd

Added enum for other-central for central tabulation that is not
absentee, and added integer for number of registered voters to both
precinct and precinct split elements.
Updated schema to match worked example of schema

Published first version of sample feed for 5.0 sample with hierarchy.
Merge pull request #3 from pstenbjorn/updates-to-spec

Updates to spec added sample and updated xsd