DEV-9761: support dynamic attribute extraction in heap only cache search


git-svn-id: http://svn.terracotta.org/svn/ehcache@7733 b9324663-ca0f-0410-8574-be9b3887307d
DEV-9761: added attribute selection test case


git-svn-id: http://svn.terracotta.org/svn/ehcache@7734 b9324663-ca0f-0410-8574-be9b3887307d