Merge DEV to HEAD

ContentDiskDriver rework.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@29451 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/filesys/repo/rules/Command.java

@@ -0,0 +1,18 @@
+package org.alfresco.filesys.repo.rules;
+
+import org.alfresco.repo.transaction.AlfrescoTransactionSupport.TxnReadState;
+
+/**
+ * A Command is something that must be done.   Commands are higher level 
+ * than Operations.    So a rule returns a command or set of commands to 
+ * implement an operation.
+ */
+public interface Command
+{
+    /**
+     * Is a transaction required to run this command?
+     */
+    TxnReadState getTransactionRequired();
+    
+
+}