updated HELIO link to the updated registry which is not linked to a particular machine
Merge pull request #1080 from dpshelio/heliofix

HELIO url update
Run automated tab to space indentation fixer.
Fix @dpshelio's comments on doc indentation.
Merge pull request #1066 from Cadair/tabs

[BigFix]: Run automated tab to space indentation fixer.
Change of image_center from pixel to data coordinates.

Hopefully this will (at least partially) fix issue #1062. If nothing
else, it will allow the centre of rotation to be specified as outside
the image.
Partial working rotate fixes.
Fixed rotation of image data
Stopped passing of NaNs to scipy's affine_transform
Fixed recenter test
Change the .T from the skimage to the scipy.

This means that the affine_transform routine rotates a C ordered
numpy array in the correct direction. This breaks FITS files.
Fix the submap thing while keeping affine_transform rotating CCW.

This however might break non-map recentre calls to affine_transform.
Flip array_center so that it matches image_center.

For some reason only @drewleonard42 knows the image_center argument to
affine_transform is (x, y) rather than (y, x). This should be fixed at a
later date.
Add SciPy NaN warning and doc.