Updated bigquery-examples content for 1,000 genomes to current variants schema

Changes included
 1. first_allele, second_allele fields are now repeated field genotype (this necessitated many changes to the structure of queries)
 1. table name change and many column name changes
 1. data has been changed from 1-based genomic coordinates to 0-based coordiantes
 1. sample_info and pedigree tables we re-created from the source
    1. which included a super population name change from ASN to EAS
    1. provenance details include instructions to pull from source and load directly into BigQuery
 1. annotation tables moved into their own dataset
 1. updates to bigrquery usage
 1. refactoring of content such that getting started material and the literate programming demo have been moved to new repository getting-started-bigquery