Aper adding wcs and support for various input data

I think this one needs more work, but can be merge as is if you prefer:

- [x] support more input data types
- [x] add unit test
- [x] add/change documentation
- [x] support more input coordinate formats
- [x] return user input coordinates and pixelcoordinates in the result table

Future:
~~accept non pixel unit for radius etc. when the wcs is provided.~~ Moved to future feature list in #131

yes, that's a good idea. The questions is whether we want this ``unit`` to
override ``data.unit`` or not?


On 16 August 2014 13:03, Thomas Robitaille <notifications@github.com> wrote:

> In photutils/aperture_core.py:
>
> > +                              .format(i), AstropyUserWarning)
> > +                return aperture_photometry(data[i], positions, apertures, wcs,
> > +                                           error, gain, mask, method,
> > +                                           subpixels, pixelcoord,
> > +                                           pixelwise_error, mask_method)
> > +
> > +    # this is basically for NDData inputs and alike
> > +    elif hasattr(data, 'data') and not isinstance(data, np.ndarray):
> > +        datamask = data.mask
> > +        if data.wcs is not None and wcs_transformation is None:
> > +            wcs_transformation = data.wcs
> > +        data = u.Quantity(data.data, unit=data.unit, copy=False)
> > +        data.mask = datamask
> > +
> > +    else:
> > +        data = u.Quantity(data, copy=False)
>
> Just a thought - do we want to add unit as a keyword argument, which a
> user can use to specify the units of the data in case they cannot pass a
> quantity for the data?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/astropy/photutils/pull/122/files#r16324508>.
>