Samtools. The test harness worked, but the samtools interface needed
an additional cram_set_header function as we don't pass this over when
opening the new cram file.
(Try#2 - previous commit accidentally rolled back an upstream change
from 2 hours before.)
Merge branch 'develop' of github.com:jkbonfield/htslib into develop
Fixed accidental roll back of upstream change.
(I tried to edit git history, but it's not playing ball so sorry for
the mess!)