Log Message:
Update sylpheed to 2.0.0.

Changes since 1.0 are:

    * New features
          o The feature for junk mail control has been added.
          o Filter rules can be applied to sent messages now.
          o Any commands can be executed when new messages arrive.
          o The move of folders has been enabled.

    * Display
          o The anti-aliased font display has been enabled.
          o Icons can be displayed with alpha-blending (translucence)
            now.
          o Attached images can be displayed as inline now.
          o The summary view (message list) now displays its rows with
            alternating row colors.
          o The icons and logo has been renewed.
          o The window icon is displayed now.

    * User interface
          o The file selection dialog has been improved.
          o URL links can be opened by single click now.
          o Right-click menu can be available on the message view now.
          o The order of the buttons now complies with GNOME HIG.
          o The folder view now automatically scrolls on drag'n'drop.
          o The columns of the summary view became reorderable by
            drag'n'drop.

    * Internal changes
          o The GUI toolkit has been switched from GTK1.2 to GTK2.
          o The internal encoding is always UTF-8 despite of the
            current locale, and the multilingual display is now
            possible.

    * Other improvements
          o The auto line-wrapping now supports proper line-breaking.
          o The algorithm of the thread display has been improved.
          o The PLAIN authentication is supported on SMTP AUTH now.
          o The read/write of the summary cache has been optimized.
          o Encryption is enabled by default now when replying to
            PGP-encrypted messages.
          o The displayed file size of attachments became more accurate.
          o The handling of header strings with broken encoding has
            been improved.