4.2.1.0
    * API changes:
        * Attr record accessor fore_color changed to attr_fore_color
        * Attr record accessor back_color changed to attr_back_color
        * Attr record accessor style changed to attr_style
        * Added an "inline" display attribute changing DSL:
            * put_attr_change applies a display attribute change immediately to a terminal
            * For instance, can be used to change the display attrbiutes of text output via putStrLn
              and putStr. EX: "put_attr_change $ back_color red" will set the
              background color to red. 
            * Changes do not apply to a Picture output via output_picture. 
            * See Graphics.Vty.Inline
        * Moved all IO actions into any monad an instance of MonadIO

4.0.0.1
    * binding for mk_wcswidth was incorrect. Most platforms just magically worked due to
      coincidence.

4.0.0
    * Completely rewritten output backend.
        * Efficient, scanline style output span generator. Has not been fully optimized, but good
          enough.
        * The details required to display the desired picture on a terminal are well encapsulated.
        * Terminfo based display terminal implementation. With specialized derivitives for xterm,
          Terminal.app, and iTerm.app. 
            * Attempts to robustly handle even terminals that don't support all display attributes.
            * I've tested the following terminals with success: iTerm.app, Terminal.app, xterm,
              rxvt, mlterm, Eterm, gnome-terminal, konsole, screen, linux vty. Hopefully you will be
              as successfull. 
        * Improved unicode support. Double wide characters will display as expected.
    * 256 color support. See Graphics.Vty.Attributes.Color240. The actual output color is adjusted
      according to the number of colors the terminal supports.
    * The Graphics.Vty.Image combinators no longer require matching dimensions to arguments.
      Unspecified areas are filled in with a user-customizable background pattern. See
      Graphics.Vty.Picture.
    * output images are always cropped to display size.
    * Significant code coverage by QuickCheck tests. An interactive test for those final properties
      that couldn't be automatically verified.

    issues resolved:
        * "gnome terminal displays non-basic attributes as strikethrough"
            * http://trac.haskell.org/vty/ticket/14
        * "Multi-byte characters are not displayed correctly on update"
            * http://trac.haskell.org/vty/ticket/10
        * "Redraw does not handle rendering a line that extends beyond screen width characters" 
            * http://trac.haskell.org/vty/ticket/13
        * "The <|> and <-> combinators should be more forgiving of mismatched dimensions" 
            * http://trac.haskell.org/vty/ticket/9
        * "256-color support" 
            * http://trac.haskell.org/vty/ticket/19