OAK-1305: Use non-orderable child nodes in FlatTreeWithAceForSamePrincipalTest
- use distinct test root node
- use non-orderable child nodes (nt:folder)
- convert tabs to spaces

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1555865 13f79535-47bb-0310-9956-ffa450edef68