doc updates
manually applying changes from https://github.com/grails-plugins/grails-spring-security-acl/pull/4
renamed ClassLoaderPerProxyBeanNameAutoProxyCreator to AclAutoProxyCreator
Manually merged https://github.com/grails-plugins/grails-spring-security-acl/pull/8
updates from https://github.com/grails-plugins/grails-spring-security-acl/pull/3