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/common/Stream.h

@@ -0,0 +1,64 @@
+/**
+ * Copyright (c) 2006-2015 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#ifndef LOVE_STREAM_H
+#define LOVE_STREAM_H
+
+// LOVE
+#include <stddef.h>
+#include "Object.h"
+
+namespace love
+{
+
+class Stream : public Object
+{
+public:
+	virtual ~Stream() {}
+
+	// getData and getSize are assumed to talk about
+	// the buffer
+
+	/**
+	 * A callback, gets called when some Stream consumer exhausts the data
+	 **/
+	virtual void fillBackBuffer() {}
+
+	/**
+	 * Get the front buffer, Streams are supposed to be (at least) double-buffered
+	 **/
+	virtual const void *getFrontBuffer() const = 0;
+
+	/**
+	 * Get the size of any (and in particular the front) buffer
+	 **/
+	virtual size_t getSize() const = 0;
+
+	/**
+	 * Swap buffers. Returns true if there is new data in the front buffer,
+     * false otherwise.
+	 * NOTE: If there is no back buffer ready, this call must be ignored
+	 **/
+	virtual bool swapBuffers() = 0;
+}; // Stream
+
+} // love
+
+#endif // LOVE_STREAM_H