Merge pull request #80 from wtsi-npg/devel

v10.13
Merge pull request #83 from wtsi-npg/devel

v10.14
Merge pull request #85 from wtsi-npg/devel

release 1.17
Merge pull request #87 from wtsi-npg/devel

Merged for release 10.16
Merge pull request #89 from wtsi-npg/devel

handle NULL states returned by getFilterData