Added DocPdf field for caching

PROMS/Volian.Controls.Library/DisplayLibDocs.cs

@@ -227,7 +227,7 @@ namespace Volian.Controls.Library
                 int nBytesRead = fs.Read(ByteArray, 0, (int)len);
                 fs.Close();
                 string t1 = (title == null || title == "") ? null : title;
-                Document doc = Document.MakeDocument(t1, ByteArray, null, null); //, DateTime.Now, "Migration");
+                Document doc = Document.MakeDocument(t1, ByteArray, null, null, null); //, DateTime.Now, "Migration");
                 return doc.DocID;
             }
             // for an io exception, keep trying