* src/procmime.[ch]

* src/procmime.[ch]
        re-added parsing of Content-Disposition header
                - removes the old  'gchar* content_disposition'
                - adds a new field 'DispositionType disposition'
                - adds parameters to MimeInfo::parameters
* src/mimeview.c
        use the "filename" parameter for saving, and the new
        MimeInfo::disposition for save all.