Added function for next_seq_id
Add dependency install of Data::Dump and configuration include for volvox-paired.bam
Robert confirmed that Data::Dump was not needed so removing from setup
Added multi_segment_next_segment_strand convinience method to simplify comparison of reads in pair
Added volvox-paired SNPcoverage test track
Added filters for unmapped reads that have mapped-mate coordinate
Updated colour scheme for multi-segment sequencing
	all-mapped f/r		: light red/blue
	all-mapped-proper f/r	: original red/blue
	next seg unmapped f/r	: hard red/blue
	all-mapped diff seq f/r	: black/grey