Add Exception Handling

[ReMiOS]

I've added some code for improved error Exception handling. for reference i've used the xpdf source from src\xpdf-4.04\xpdf\ErrorCodes.h

//========================================================================
//
// ErrorCodes.h
//
// Copyright 2002-2003 Glyph & Cog, LLC
//
//========================================================================

#ifndef ERRORCODES_H
#define ERRORCODES_H

#define errNone             0   // no error

#define errOpenFile         1   // couldn't open the PDF file

#define errBadCatalog       2   // couldn't read the page catalog

#define errDamaged          3   // PDF file was damaged and couldn't be
                // repaired

#define errEncrypted        4   // file was encrypted and password was
                // incorrect or not supplied

#define errHighlightFile    5   // nonexistent or invalid highlight file

#define errBadPrinter       6   // invalid printer

#define errPrinting         7   // error during printing

#define errPermission       8   // PDF file doesn't allow that operation

#define errBadPageNum       9   // invalid page number

#define errFileIO          10   // file I/O error

#endif