Huge new version!

Version 4.0 has been released. The new version reads files much faster. Even files with images can now be read in less than a second.
The UI has also been completely redesigned, and now features a toolbar and status bar in place of the buttons and menus.
Also added is an automatic update checker. It checks for updates on startup, and can be turned on and off. You can also update manually from the options screen.