Revert Maven groupId for connector bundles from singular to plural form (connectors)

In PR #22 we have updated Maven groupId for connector-bundle-parent project from org.forgerock.openicf.connectors to org.wrensecurity.wrenicf.connector (note the singular form of connectors). In hindsight I dislike this change for a few reasons:

• this makes everyone migrating from the old groupId to do an additional change other than simple organization name switch
• groupId is being used in connector bundle name so that is already two places where the subtle change has to happen
• if we take a look at for example Maven plugins, they are using plural as well
• the reason for removing the plural can be reasoned for in the case of connector-bundle-parent (which is what I did), but as it inherited by the connectors, that is where it became problematic

So I propose to change it back to the plural form. The unfortunate thing is that we have already released quite a lot of projects with the updated groupId. In that sense this would be a breaking change, however all those releases are very recent, so if we want to do this, it is now or never. The following projects have to be updated:

• wrenicf-java-framework
• wrenicf-csvfile-connector
• wrenicf-databasetable-connector
• wrenicf-groovy-connector
• wrenicf-kerberos-connector
• wrenicf-ldap-connector
• wrenicf-ssh-connector
• wrenicf-xml-connector
• wrenidm

Start with the connector-bundle-parent Maven configuration, then inspect the groupId declarations and inherited values in wrenicf-java-framework, the listed connector projects, and wrenidm. Verify which released identifiers use the singular form and update the affected project configurations so the connector groupId consistently uses the plural form.