purple-v2.31

Added microsatellite status
Added subclonal likelihood model and figure
Consistent file headers
Consistent file names
Fix whole genome duplication calculation
Changed definition of ref_genome parameter to be mandatory path to reference fasta file.
Added REP_S, REP_C, MH, TNC, KT fields to somatic vcf output
Added REF_G to structural vcf output
Added variant rainfall plot