Merge pull request #20 from wtsi-npg/master

pull release 56.6 from wtsi master to devel
bug fix, only insert values which exist
updated Changes file for release 56.7
Make regex critic compliant
Merge pull request #5 from dkj/srl_cluster_density_fix

Make regex critic compliant
Merge pull request #21 from srl147/devel

bug fix, only insert values which exist
Merge pull request #22 from wtsi-npg/devel

release 56.7