Use some additional bindings in media player

I've added these functions to media player :
* setTime -> allow to seek in a file at a position in ms (libvlc_media_player_set_time) 
* getTime -> get file position in ms (libvlc_media_player_get_time) 
* setPosition -> allow to seek in a file at a position in percent (from 0.0 to 1.0) (libvlc_media_player_set_position) 
* getPosition -> get file position in percent (from 0.0 to 1.0) (libvlc_media_player_get_position) 
* setX11Window/setWin32Window/setOSXWindow -> allow to set a window for libvlc output. Useful if you don't want to be limited to directfb output (node-qt, node-x11). 

I've fixed types in libvlc_media_player_set_time and libvlc_media_player_get_time bindings by replacing "longlong" by ref.types.int64.