Let WrappedImg extend Img

[ctrueden]

And add default method implementations delegating to the wrapped Img.

I lifted the methods to implement from an existing class implementing WrappedImg and Img with the delegation pattern.

I'm not sure this is actually a good idea. It would slightly reduce the flexibility of the WrappedImg interface, such that you could no longer implement the two interfaces with different type parameters e.g. WrappedImg< FloatType > and Img< DoubleType >. One scenario where you might want to do that, I guess, could be if you are creating adapter classes from one type to another? E.g. if we consider the Converters utility method:

< A, B extends Type< B > > WriteConvertedRandomAccessibleInterval< A, B > convert(
			final RandomAccessibleInterval< A > source,
			final SamplerConverter< ? super A, B > converter )

And one can imagine a similar function accepting an Img< A > source instead and returns a WriteConvertedImg< A, B > that implements WrappedImg< A > and Img< B >.

A way around that could be to instead introduce a new interface WrappedImgImg< T > extends WrappedImg< T >, Img< T > and have the default delegation methods at this layer. Then folks who want the convenience of these delegators could implement WrappedImgImg instead of the two lower-level interfaces.

Thoughts?