diagnostics and lower FPR

v0.2.3

• save disc and split counts and output a plot as QC
• annotate: annotate with up and downstream 5KB. so any gene within 5kb will be annotated.
• smoove merge now outputs a plot that shows the number of split and discordant reads for each sample.
• smoove now filters about 25% more split reads by looking at how the read is consumed
  this results in a 5% reduction in false positive genome-in-a-bottle deletions > 1KB while leaving
  the true positives unchanged relative to version 0.2.2. (Thanks @ernfrid for feedback on this feature).