Change property pixeldata to data

[martinberoiz]

I think the method returning the ndarray pixels from SingleImage should be just data instead of pixeldata, since that seems to be the standard in masked numpy arrays, CCDData, NDData and HDUList.

Likewise it should have a property mask that returns the mask as a ndarray, but I think that is already implemented.

I don't know what you guys think.

[martinberoiz]

Oh, and the __init__ method should have the keyword data for the ndarray instead of img as it is now.

[BrunoSanchez]

Would you prefer that mask is a property separated or that data is a masked array?

[martinberoiz]

I think that data should return a plain ndarray (no mask) and mask return just the mask.
So, yes, the property mask to be separated from data, but internally you can keep them as a masked array, as long as this isn't exposed publicly.

BTW I think this change would break API.