allow embedded broker with kahaDB to exit without stop - make writer threads Daemon

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@814649 13f79535-47bb-0310-9956-ffa450edef68

activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java

@@ -245,6 +245,7 @@ public class MessageDatabase {
 	                }
 	            }
 	        };
+	        checkpointThread.setDaemon(true);
 	        checkpointThread.start();
             recover();
 		}

kahadb/src/main/java/org/apache/kahadb/page/PageFile.java

@@ -1109,6 +1109,7 @@ public class PageFile {
                     }
                 };
                 writerThread.setPriority(Thread.MAX_PRIORITY);
+                writerThread.setDaemon(true);
                 writerThread.start();
             }
         }