Create two new public methods in Excel so a user could access the workbook using java code like this: (#182)

java com.genexus.gxoffice.poi.xssf.ExcelDocument document = (com.genexus.gxoffice.poi.xssf.ExcelDocument)[!&ExcelDocument!].getDocument();
java org.apache.poi.ss.usermodel.Workbook workbook = document.getWorkBook();

Author: iroqueta

gxoffice/src/main/java/com/genexus/gxoffice/ExcelDoc.java

@@ -51,6 +51,12 @@ public short getReadOnly()
 
 
 	IExcelDocument document;
+
+	public IExcelDocument getDocument()
+	{
+		return document;
+	}
+
 	public void checkExcelDocument()
 	{
 		if(document == null)

gxoffice/src/main/java/com/genexus/gxoffice/poi/xssf/ExcelDocument.java

@@ -291,6 +291,11 @@ public String getTemplate()
       return template;
     }
 
+    public Workbook getWorkBook()
+	{
+		return workBook;
+	}
+
     protected String template="";
     protected Workbook workBook;		
     protected String currentSheet;