When you want to use OSD, you have to register an OSD channel, by calling
vout_RegisterOSDChannel, then pass it to vout_CreateSubPicture.
There is a particular channel, DEFAULT_CHANNEL that can be used for
general purpose.
See modules/control/hotkeys.c for an example.

  fixes a problem with missing strcasestr on platforms in combination with ncurses intf.

plain text to SVG. It can be used to have more control on the subtitle
rendering.

	- set_volume
   	- get_volume
	- mute
	- clear_playlist
	- add_item
	- next
	- previous
	- isplaying
	- ge_length
	- get_position
	- get_time
	- seek

* Fixed VLC_VolumeSet and a description

   This only works when the skins2 interface is active.
   Not very much tested yet...

* Updated text display to new API (added i_channel)

 * modules/control/hotkeys.c: don't display OSD slider if stream is not seekable, when pressing 't' hotkey.