Fix SQL error with Merge entities and don't ignore some errors

Link to SF Tracker: http://sourceforge.net/support/tracker.php?aid=2936826

client/src/org/compiere/apps/form/Merge.java

@@ -160,7 +160,7 @@ public class Merge
 			}
 			//
 			if ( success )
-				m_trx.commit();
+				success = m_trx.commit();
 			else
 				m_trx.rollback();
 			
@@ -170,6 +170,7 @@ public class Merge
 		catch (Exception ex)
 		{
 			log.log(Level.SEVERE, ColumnName, ex);
+			success = false;
 		}
 		//	Cleanup
 		try