Do it for all packages that
* mention perl, or
* have a directory name starting with p5-*, or
* depend on a package starting with p5-
like last time, for 5.18, where this didn't lead to complaints.
Let me know if you have any this time.
Class::DBI::BaseDSN acts as a placeholder for a base class which will be
switched for a specific Class::DBI extension when you specify the dsn of the
database to connect to. For example in this case, the Class::DBI::BaseDSN will
replace itself with Class::DBI::mysql when the set_db call is executed.