Fixes:
- skip bogus modified base data in .mod bams due to calls outside bounds of hard-clipped secondary/supplementary alignments
- `locus`/`region`: use "gene_id" if "gene_name" not in .gtf attributes
- various fixes to mod .bam handling, particularly around single base motifs
Features:
- `composite`: add --meanplot_cutoff, --output_table, --minelts, --maxelts options
- `locus`/`region`: add --plot_coverage option (experimental)
- depreciate `db-guppy`
- `scoredist`: support mod .bam