Ref JIRA #62 - Added identifier info to onDelete handler map too [https://jira.grails.org/browse/GPAUDITLOGGING-62]
Merge remote-tracking branch 'origin/pr/9'
 - cleanup
Merge remote-tracking branch 'origin/master' into exp
 - work on datasource and id mapping config
 - allow to specify AuditLogEvent id type mapping in config