TODO
  * several vobs pro menu
  * several audio files -> languages
  * buttons: select audio and subtitles, jump cell 1
  * add exit command to title post command drop down list
  * change icon for video+audio titles
  * two lines of text in a button
  * subtitles
  * slideshow
  * add a possibility to change the number of frames generated for the menu
  * add music to menu
  * show new dialog by first start
  * fix generation under win98
  * fix saving of filenames with stressed letters in dvdauthor.xml
  * button properties: replace direction "auto" with "auto (buttonX)"
  * menu properties: background stretch option, alignment
  * colour dialog: store custom colours
  * buttons: default fonts and colours
  * text: background color & alpha channel value
  * prompt before deleting (menu obejct, title)
  * select multiply menu objects
  * timeline
  * changed attributes (f.e. charpters) of multiply titles at once
  * context menu: play/add movie, assign as background
  * progress dialog: save log
  * fullscreen
  * resume the creation of DVD
  * don't use dnd if it not avaible (for wxUniv package)
  * rememebering last directorys or possibility to set these (dirtree, open dialog)
  * rememebering recent projects
  * video-thumnails
  * select the language for different audio streams
  * ability to mux text based subtitles to videos
  * support of .wav, .avi, .vdr
  * fix menu display (pal: 75x80 dpi, ntsc: 81x72 dpi)
  * menu language property
  * creation of audio DVDs with builtin mp3 converter out of different formats plus mp3 tracking editor