Convert aligned records to BED or other suitable format for viewing in IGV

[nh13]

If we are aligning a single read to multiple contigs, we may get multiple multi-contig alignments. We want to view those in IGV, but IGV doesn't do the best job of visualizing those alignments from BAM when we have 3+ records in a chain.

We could have a BED file with a track per alignment group, or something else.