Becareful with the function addMatch(ADQLObject, ADQLIterator): the iterator may be null if the match to add is the root search object itself!
No modification needed in SimpleReplaceHandler: Null test already done :-) !

ADQL: Completely change/improve Joins management, and particularly NATURAL JOIN and USING JOIN. Now, every joined columns are represented by a DBCommonColumn instance which has a given table coverage.
Before, there was a problem while using at least 3 or 4 NATURAL JOINs. Bug raised by Menelaos Perdikeas (ESAC).

ADQL: Fix ArrayIndexOutOfBoundsException while initializing a DefaultUDF (User Defined Function) object with several parameters.