Removing the comments from postgres upgrade script as ant upgrade fails because of these.
New SQL tables and db upgrade scripts that define a new table stucture for identifiers and delete the previously unused accession_number table. This is in anticipation of supporting LSID identifiers. Currently these tables are unused by the servlet but are in place for discussion.
Bugfixes to the previous commit and adding comments etc.
Changes to the upgrade script so that 'IN' and 'NOT IN' are not used in the queries and hence the upgrade script is much faster.
Adding new files for upgrading version 1.5 database to version 1.6 database