Use bcftools to reheader files.
Use bcftools to reheader files.

Avoids picard use here which does not support VCF 4.3, since it is using
htsjdk which doesn't support writing 4.3 yet. Partially addresses

chapmanb/bcbio-nextgen,lbeltrame/bcbio-nextgen,chapmanb/bcbio-nextgen,lbeltrame/bcbio-nextgen,lbeltrame/bcbio-nextgen,chapmanb/bcbio-nextgen