copied from cchmc, fixed bugs

THE META-ANALYSIS SCRIPT FOR PARENTAL-ORIGIN GWAS: generates meta-results for each chromosome, prunes and saves. Feeds on per-chr result files (with multiple statistical tests each) generated by Ge's script for each cohort (MoBa,DNBC,FIN,GPN,HAPO). Designed to work on CCHMC server, where the per-cohort analyses result files are stored. Can take any combination of cohorts with any number of tests.