Unable to determine buffer length (so as a hack I over allocate buffer and read)
```
byte[] buffer = new byte[width * height * 4];
int len = imageInput.read(buffer);
```
Added test files for all supported formats.
Nasty hack to get initial plugin working...
Mark and Reset the imageinput stream when reading the header. Then read the whole buffer into DDSReader and generate a fixed BufferedImage ignoring the getDestination() BufferedImage.
Paul Allen