biology/mca-calling: Core tools for mCA event calling

The mca-calling meta-port provides the core tools needed for performing
a typical mCA (Mosaic Chromosomal Alteration) analysis, including
conversion of SRA VCF files to a format suitable for haplohseq and
MoCha, and haplohseq and MoCha event calling.  The GWAS analysis that
follows is typically done with R-based tools installed within R.