* Cosmetic fix to misc.m

* src/video_output/video_widgets.c: Added OSD sliders when changing volume or position with hotkeys.
Those sliders are graphical (ie not written with characters) and we can now add others OSD "widgets".

  It doesn't support regexp for now.
* fixed a bug when playlist was empty at start

 if we find them. (Avoid dropping the first frame).

* ALL: bumped version number to 0.7.2.

* modules/gui/wxwindows/menus.cpp: release the wxMutexGui lock before triggering object var callbacks.

    + Use the svlc shortcut for skins 2, too.

* modules/gui/wxwindows/open.cpp: simplified a string (sorry for the translations) because it was making the open dialog way too big.

* added an open button