Validate modified

[konstin]

As I don't expect all vendors to properly implement modified, there should be some way to validate modified, either it as core part of this validator or as external script shipped with the validator.

The tool shall compare an older dump with a new one and check that for every modified object, the modified timestamp has been updated since the last dump. It shall also check that created is a timestamp after the last dump for all newly added objects.

[eFrane]

So, maybe we can offer general correctness of modified fields in the validator core and said script for more in-depth validation. It might even be feasable to add the latter to the to-be-implemented online validation service.