moved hibernate.cfg.xml to src/resources to prevent copying empty file to application's grails-app/conf/hibernate while packaging plugin

Since v.3.6.10 hibernate.cfg.xml template has been placed in src/java dir. In this case, after cleaning an application, hibernate.cfg.xml template file is being copied to work/resources/ dir on 'grails package' goal, overwriting cfg.xml from grails-app/conf/hibernate. It was described in details here - http://jira.grails.org/browse/GPHIB-14