Add initial video playback support for Ogg Theora videos (resolves issue #66.)

The basic APIs are:

video = love.graphics.newVideo("myvideo.ogv")

love.graphics.draw(video, ...) -- Video objects are Drawables.

video:play(), video:pause()

video:getDuration(), video:tell(), video:rewind(), video:seek(seconds)

video:getSource()

video:getWidth(), video:getHeight(), video:setFilter(min, mag)

More advanced APIs include video:setSource(source), video:getStream(), and videostream:setSync.

To use a custom pixel shader when drawing a Video, call the new TexelVideo(texcoords) function instead of Texel(texture, texcoords) in order to get the pixel colors of a video frame.

src/modules/sound/lullaby/VorbisDecoder.cpp

@@ -168,7 +168,7 @@ bool VorbisDecoder::accepts(const std::string &ext)
 {
 	static const std::string supported[] =
 	{
-		"ogg", "oga", ""
+		"ogg", "oga", "ogv", ""
 	};
 
 	for (int i = 0; !(supported[i].empty()); i++)