Fixed bug in TableBuilder copy columns from table
Dropped support of the automatic filed names in TableBuilder.

The TableBuilder no longer supports the method columnAuto without
the field name. Has been removed the support of automatic field
guessing to avoid performance issues.
EntityMapper now returns null when find a null row

From now the EntityMapper returns null if find a null row. A null row
is when the entity ID is selected and has a null value.
More work on samples for tables inheritance
Renamed Related and RelatedInverse to RelatedParent and RelatedChild