Alterações na distribuição 3.21.24

Dynamic loadable functions. Based on source from Alexis Mikhailov.

You couldn't delete from a table if no one had done a SELECT on the table.
Fixed problem with range optimiser with many OR operators on key parts inside each other.
Recoded MIN() and MAX() to work properly with strings and HAVING.
Changed default umask value for new files from 0664 to 0660.
Fixed problem with LEFT JOIN and constant expressions in the ON part.
Added Italian error messages from <brenno@dewinter.com>.
configure now works better on OSF/1 (tested on 4.0D).
Added hooks to allow LIKE optimization with international character support.
Upgraded DBI to 0.93.