introspect the real reason behind PR #13

[jensens]

see #13

by @pbauer:

plone.dexterity.schema.generated.plone_0_LockableType has zope.interface.adapter.VerifyingAdapterLookup as a dependent which again has no dependents.

• Maybe VerifyingAdapterLookup should not be here or it should have dependents (a weakref.WeakKeyDictionary())
• Maybe also related to the comment below which states that the first base class of a schema must be a SchemaClass.

[ale-rt]

The patch introduyced in #13 was removed in c1822bb
But we have no clue why it became not necessary anymore

[jensens]

This "esoteric code" (tm) is all for the sake of testing if the directives are correct AFAICT. Question is if this is can be achieved different, with that much boilerplate code.