features:
    - message copy/move
    - message delete/undelete
    x message status display (icons in message list)
    x mailbox with new messages should be higlighted (bold)
    - better save attachment dialog
    - attachment should be  displayed as icon with text
    - attachment handling based on mime-type
    - message send (local send via sendmail)
    - mark message read if it is viewed at least N secs
    x mailobx/folder add/delete
    x next/previous message toolbar buttons
    x complete message parsing (partialy completed)
    x image displaying
    x message-list sorting
    

- bug fixes:
    x incorect header parsing when last header field has no value
    x tmp file handling
    x images are not correctly displayed
    x last char of message isn't displayed


- memory leaks:
    - everywhere