Fix validation - tests were failing.

for a good time, pdb down the validator chain.
Version bump 3.1.4.1

Conflicts:
	CHANGELOG.txt
ar/publish: AttributeError getBatchLabels.

The default accessor is missing in some specific contexts, I don't
know what makes them special, but I don't have to because the
following works:

    uids = batch.Schema()['BatchLabels'].getAccessor(batch)()
LIMS-1369: custom_actions is not a required field

so it's ok if it's not present in the table layout props
Merge branch 'hotfix/next' into develop