Revert deprecating a class that we still use ourselves and update error text slightly

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1771395 13f79535-47bb-0310-9956-ffa450edef68

src/integrationtest/org/apache/poi/stress/POIXMLDocumentHandler.java

@@ -44,7 +44,7 @@ public final class POIXMLDocumentHandler {
             } finally {
                 poifs.close();
             }
-            throw new IOException("wrong file format or file extension for OO XML file");
+            throw new IOException("Wrong file format or file extension for OO XML file");
         }
         return false;
     }

src/java/org/apache/poi/hssf/OldExcelFormatException.java

@@ -17,12 +17,7 @@
 package org.apache.poi.hssf;
 
 import org.apache.poi.OldFileFormatException;
-import org.apache.poi.util.Removal;
 
-/**
- * @deprecated POI 3.16 beta 1. Use {@link org.apache.poi.OldFileFormatException}
- */
-@Removal(version="3.18")
 public class OldExcelFormatException extends OldFileFormatException {
 	public OldExcelFormatException(String s) {
 		super(s);