When there is eg both "antisense" and "snoRNA" at a locus, how do we want to count them?

4 ways:

• alphabetically sorted and joined
• Count all of them (adds up to more than 100%)
• Probabalistically - ie fractionally count (ie .5 if 2)
• Count the "most important" (ie in an order)

These should be command line options in bam-biotype