add SkyCoord.position_angle and associated test
implemented @mhvk's suggestions from PR #2487
Add changelog entry
Update docstring to get rid of doctest failure
Generate args as a list.

Fix #2488.
Handle unicode in the config file.

Fix #2481.
Fix parallel argument.
Allow for supplying a single unit in SkyCoord
Improve exception error message for bad unit input
Merge pull request #1421 from taldcroft/coordinates-single-unit

Coordinates should accept a single unit value to apply to all parameters
Merge pull request #2487 from eteq/add-position-angle

add SkyCoord.position_angle and associated test
Fix for Python 2.x
Add changes entry.
Merge pull request #2489 from mdboom/config/encoding

Handle unicode in the config file.
Merge pull request #2488 from mdboom/misc/spaces-in-path

python setup.py test fails if there are spaces in the directory path
Let Quantity get its units from the `unit` attribute even for a non-Quantity
Try to convert to unit instead of isinstance check
Rescale when a non-Quantity input to Quantity has 'unit', instead of ignoring
Updated docstring to reflect additional options of input for Quantity
Add changelog entry

[ci skip]