RNA-seq qualimap: replace sambamba count with hts-nim-tools
RNA-seq qualimap: replace sambamba count with hts-nim-tools

Avoids issues on systems that segfault with sambamba. Thanks to @ohofmann
and @vladsaveliev

lbeltrame/bcbio-nextgen,lbeltrame/bcbio-nextgen,vladsaveliev/bcbio-nextgen,a113n/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,lbeltrame/bcbio-nextgen,vladsaveliev/bcbio-nextgen,chapmanb/bcbio-nextgen,a113n/bcbio-nextgen,chapmanb/bcbio-nextgen,chapmanb/bcbio-nextgen