[horde] What is horde_histories for?

[Otto Stolz]

PPS.

my beta-test version (Horde 3.1.3 + Imp 4.1.3 + Turba 2.1.3,
with data imported from the old production version Horde 2.2
+ IMP 3.2 + Turba 1.2) one field that is not created
by horde/scripts/sql/create.mysql.sql, viz.
- table: horde_datatree_seq, field: datatree_updated.

What about this? Is it no longer required? Should I
drop it from the beta-test version, or should I add it
to the forthcoming production version?

Thanks for any insight.

Best wishes,
    Otto Stolz