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.
Merge pull request #324 from jwoillez/fixes_for_astropy0.4

Many fixes for astropy0.4 and remote tests