The date format is now selectable.

Added the form controls and AppSettings keys to allow the user to select
the format of the date appended to the output file.
Further update to issue #1.

AboutBox1.cs

@@ -37,7 +37,7 @@ namespace PDF_Merge
                         return titleAttribute.Title;
                     }
                 }
-                return System.IO.Path.GetFileNameWithoutExtension(Assembly.GetExecutingAssembly().CodeBase);
+                return Path.GetFileNameWithoutExtension(Assembly.GetExecutingAssembly().CodeBase);
             }
         }