Add vcf-downsample subcommand
Improvements to build system
extract-seq: Recurse to output subfeatures
Numerous other minor enhancements and fixes
Changes: https://github.com/auerlab/biolibc-tools/releases
Biolibc-tools is a collection of simple, fast, and memory-efficient
programs for processing biological data. These programs built on
biolibc are not complex enough to warrant separate projects.