tune debugMessage - make sure we add the ArJdbc: prefix as well
remove DB2's unused (previous) identify_val_local implementation
[oracle] fix missing sequence_name_length method when doing a rename_table
make sure ArJdbc::Oracle::Column still works as in 1.3.x
[oracle] no need to rescue RENAME/DROP SEQUENCE errors programatically

also default_sequence_name yet again borrowed from orancle-enhanced ...
potentially missing (invoker generator) annotations
finish the matchTables / mapTables refactoring - so it's possible to roll wout meta-data
these introduced with 927aa0d6f20de fail on AR 2.3 ... simply do not care for now