Allow use of externally defined reference file

If REF_FILE variable is set, that file will be used as reference to
determine the old copyright year. If not, core.php will be used.
More descriptive filename for db cleanup script
Use a single update statement instead of 4
Define the realname
New script to dump and anonymize Mantis DB

Script will create a clone of the specified mantis database, run
db-anonymize.sql script to cleanup the data, then dump the clone in
compressed format in the target directory.
Database dump script