Use Python 2 /3 compatible source (no 2to3)
Remove bundled astroquery/extern/six.py
Use astropy.extern.six instead of Astroquery bundled version
Fix monkey patching of urllib in test_utils.py
Fix ImportError on Python 3
Python 3 fixes (so that it works without 2to3)
Minor Python 3 fix in splatalogue pointed out by @keflavich
Missing html import in Eso.query_survey()
Fixed failing Eso remote tests
Replaced commons.radius_to_unit by Angle()
Replaced deprecated UnitsException by UnitsError
Updated error message in irsa_dust test.
Fixed urlopen use.
Removed radius_to_unit tests.
Fixed handling of duplicated form inputs
Do not add forms inputs without name to payload
Updated documentation for Eso package.
Minor sphinx improvement.
Added help option to Eso.instrument_query()
Improved Eso.query_instrument() interface.

Using `columns` and `column_filters` keywords instead of the generic
`**kwargs`.