Several FrameGrabber interfaces return int instead of size_t

[drdanz]

The following methods should return size_t instead of int:

• IFrameGrabber::getRawBufferSize
• IFrameGrabber::height
• IFrameGrabber::width
• IFrameGrabberRgb::height
• IFrameGrabberRgb::width
• IFrameGrabberImage::height
• IFrameGrabberImage::width
• IFrameGrabberImageRaw::height
• IFrameGrabberImageRaw::width

There might be more, this was just what I found doing a quick check