FELIX-3978 - Check that we don't use java 6+ API

Configure animal sniffer.
Fix one occurrence of a java 6 API use


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1458704 13f79535-47bb-0310-9956-ffa450edef68
Removing the requirement to provide the default realm name explicitly. By default in absence of any explicitly defined realm name it would be assumed to be 'default'

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1458705 13f79535-47bb-0310-9956-ffa450edef68