Date modified needs system maintenance

[leskneebone]

Consider automating date modifications for concept scheme with system maintenance.

Stamp Date modified on saving concept scheme after changes to attributes (e.g. pref label, definition, version etc) but NOT for new relationships (such as hasTopConcept).

Perhaps retain a manual override for Date modified. I can't think of a use case for that - might need discussion.

[edmondchuc]

This is a good idea. I will look at this soon.