and other cosmetic fixes

* complete l10n support

The usage of the logo-filter doesn't work here, but that might be because of my strange PNG-files. I'll investigate this tomorrow.

It would be nice if some of the OSX-devs and testers could check whether everything works as expected, whether you are able crash the entire thingie, etc.
Note that on-the-fly activation of filters doesn't work (this needs the vout-rework scheduled for 0.8.5).

* removed the controls used for fixed positioning, because they conflict with the relative controls and aren't used by most of the users anyway
* fixed 10.3 compatiblity

still TODO:
- implement the logo and time controls completely
- l10n
- FIXMEs

Fix a bug in delete

* modules/access/rtsp/rtsp.c: fixed major bug in realrtsp access. Some incoming data would occasionally be dropped.

  with --enable-corba, but it can now be used through the python binding)

   were drawn when resizing the layout)

and stop doing different things with net_OpenUDP()

* modules/codec/realaudio.c: try to detect dropped subpackets so we don't screw-up the subpackets reordering.

+ popup compile fix (bonus !)

 * doc/skins/skins2-howto.xml: Added documentation for this attribute

* modules/gui/wxwidgets: display and resizing of the embedded playlist should behave a lot better now.

* Don't expand nodes by default
* Distinguish notification types from document to view
  ( update of one item, global change, append of one item)
* Handle item-append 
   - Add a command/callback
   - TODO: Only rebuild the tree image if the newly appended item is 
     visible
* Rename m_lastPos to m_firstPos as it represents the first position
* Beginning of a general ensureVisible function (not working yet)

   XML example:
       <PopupMenu id="sample_menu">
           <MenuItem label="Play" action="vlc.play()" />
           <MenuItem label="Pause" action="vlc.pause()" />
           <MenuSeparator />
           <MenuItem label="Show playlist" action="playlist_window.show()" />
           <MenuItem label="Hide playlist" action="playlist_window.hide()" />
           <MenuSeparator />
           <MenuItem label="Quick open file" action="dialogs.fileSimple()" />
       </PopupMenu>

   To call the menu:
       <Button action="sample_menu.show()" ... />

   Known bug: the popup disappears when the user clicks "too fast" on the
   button: the control refreshes itself in an asynchronous way, and the popup
   dislikes it... so click slowly :)