Added "package_exec_plsql" which, like "package_instantiate_object", allowsone to call PLSQL from Tcl, which reduces the need for oracle/pg-specificXQL files.
Fixing auto-generation of usernames when email was already taken. Since (username) is empty on that point the following query never returned any rows and xxx-2 was always created, so it failed if xxx-2 was already existing.