JobLockService implementation

- Provides transaction-aware locking
 - Post-transaction cleanup is automatically done
 - Retrying for lock acquisition is handled internally as well
 - Downgraded the lock concurrency tests for the build machine (maybe 50 threads was too much)
 - Deadlock tests added for the high-level locking


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@13968 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/domain/locks/AbstractLockDAOImpl.java

@@ -117,7 +117,7 @@ public abstract class AbstractLockDAOImpl implements LockDAO
             {
                 throw new LockAcquisitionException(
                         LockAcquisitionException.ERR_EXCLUSIVE_LOCK_EXISTS,
-                        lockQName, lockToken);
+                        lockQName, lockToken, existingLock);
             }
             existingLocksMap.put(existingLock, existingLock);
         }