0.22.0

• new template for minimap2 alignment, with optional post-alignment filtering of secondary and supplementary alignments, and minimap2_F_value parameter to allow non-default insert size to be specified (-F flag)
• subsampling of 10K reads (fastq produced by samtools view -s SEED.FRAC) and production of fastqcheck files added to stage1 and stage2 analyses (nchs, single-/paired-end)
• add lane-level samtools stats to stage1
• spatial filter application moved to stage2 from stage1
• amend spatial_filter input/output file names for easier identification
• empty edge entries recognised as noop - filter in viv.pl, ignore in visualisation, do not apply VTFILE
  prefixes when there are no to and from attributes