Implement a "delta report"

[pkiraly]

KBR runs the application on daily basis. They provide a 'daily changes' type of update that contains only those records that has been added or modified the previous day. So far QA catalogue process merge them to the full catalogue, and ran the analyses on the whole set. KBR would like to have a validation report of this daily updates as well. Maybe it is worth to call this feature as "delta report" because at other libraries the frequency might be weekly, monthly or other.