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.
Use temporary file instead of named file in aiaprep test.
Clean up ANA tests and make them skip if ANA not present or on windows

Also make all jp2 tests skip if glymur is not present.
Fix up all glymur and ANA tests so they are skipped.
Helioviewer test needed a skip_glymur.
Same tempfile trick on the map factory test.
Make ana use tempfile instead of hard coded files.

closes sunpy/sunpy#744
bump pandas and astropy on Travis.
Update Astropy requirement everywhere.
remove redundant exception docs from database.rst

This works-around a werid doc bug. see astropy/astropy_helpers#37
test with the latest version of suds-jurko.
Fixed unintended modification of input image