hsmetrics fails on non-human genomes

[percyfal]

We currently use agilents sureselect per default for calculating hs_metrics. hsmetrics calculations will fail for non-human genomes since the sequence dictionaries differ (i.e. chromosome lists):

Caused by: net.sf.samtools.util.SequenceUtil$SequenceListsDifferException: Sequence dictionaries are not the same size (1, 93)

Suggested solutions:

1. run hs_metrics manually for relevant samples for now

2. put target files in directory structure in which genome can be deduced, and if genome_build differs, don't run hs_metrics