Merge branch 'release/2.5.1'
Update git submodule reference for CSF.Core project

The location of the main CSF software utilities has changed (it is now named
CSF.Core and not csf-software-utilities).  Also the github organisation has
changed from "CSF-Software-Development" to "csf-dev".
Resolve #6 - Remove reference to obsolete functionality of IEntity.
Bump version numbers
Merge branch 'release/2.5.2' into production