HHH-8737 deprecated UniqueDelegate, created StandardUniqueKeyExporter,
stripped SQL generation from metamodel.spi.relational constraints,
created applyConstraints/dropConstraints on Dialect
HHH-8737 pulled applyConstraints/dropConstraints into a new
ConstraintDelegate, created UK exporters for DB2 and Informix
HHH-8737 handle permutations of conflicting indexes and unique keys, set
explicit FK names, corrected default annotation values, initial unit
test
HHH-8737 log warnings if duplicate constraints/indexes would have been
created