Fix #1374: `to_string()` should return a real string when it is a scalar.
Remove AngularSeparation class
Pass Angles (not radians) into sphere_dist computation for separation
Convert separation to Angle in degrees in one step, not two
Update doc example for Angle output
Update CHANGES.rst for removal of AngularSeparation
Merge pull request #1007 from taldcroft/delete-ang-sep

Remove AngularSeparation as a distinct class
Merge pull request #1374 from mdboom/coordinates/angle-to-string-scalars

Angle.to_string() returns a 0-d array with dtype=object
Fix angle doc examples after #1374
Merge pull request #1399 from taldcroft/angle-object-docs

Fix angle doc examples after #1374
Partial fix for #1387: Angles are not properly parsed when the given unit and the unit in the string do not match
Fix angle bounds error message
Merge pull request #1388 from mdboom/coordinates/angle-unit-parsing

Fix angle/unit parsing
Add copy parameter to quantity instantiation; set it to False wherever the
value instantiated is already known to be a copy.
Also adjust __quantity_instance__ in Angle, though incomplete pending #1310
Replace repeated parameters in __quantity_instance__ with **kwargs
Ensure angles can deal with copy option
Small corrections for documention of copy option in quantity.py
Also ensure copy arguments get passed on if given to Longitude/Latitude