Computes intersection between a VCF dataset and a set of genomic intervals defined as either a BED dataset (http://genome.ucsc.edu/FAQ/FAQformat.html#format1) or a manually typed interval (in the form of chr:start-end).
VCFBEDintersect is based on vcfintersect utility of VCFlib toolkit developed by Erik Garrison (https://github.com/ekg/vcflib).