Added headers to DataWindow source code

Source/Processors/Visualization/DataWindow.cpp

 /*
-  ==============================================================================
+    ------------------------------------------------------------------
 
-    DataWindow.cpp
-    Created: 8 Feb 2012 1:10:13pm
-    Author:  jsiegle
+    This file is part of the Open Ephys GUI
+    Copyright (C) 2012 Open Ephys
+
+    ------------------------------------------------------------------
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-  ==============================================================================
 */
 
 #include "DataWindow.h"