Add another test file for bug #47251, from Joe Yuan, and a disabled test

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1583825 13f79535-47bb-0310-9956-ffa450edef68

src/testcases/org/apache/poi/hssf/usermodel/TestBugs.java

 
     @Test
     public void bug47251() {
+        // Firstly, try with one that triggers on InterfaceHdrRecord
         openSample("47251.xls");
+        
+        // Now with one that triggers on NoteRecord
+        // TODO Fix the bug and enable this bit of the test
+        //openSample("47251_1.xls");
     }
     
     /**