Fixed checkbox handling

Reject when not checked!
Added debug statement for form payload
Updated download link
Allow login() with no username

You will be asked for it…
Added test for retrieve_data()

MIDI is my favorite of the moment, sorry AMBER!
If no username specified, use configured one.
Marked the retrieve_data test as fail for now
Typo...
Updated CHANGES.
ALMA: automatically determine which archive to go to if the generic one
is selected
only need the local archive for data retrieval.  It is not allowed to
check remote services upon __init__.
query_region_async needs to pass on kwargs
need to actually use the function I wrote
Merge pull request #424 from keflavich/alma/archive_url

More ALMA bugfixes: almascience.org doesn't accept rh/submission
Add authenticated() to QueryWithLogin
Force login() is needed in Eso.retrieve_data()
Updated Eso documentation for automatic login/password
Doc: Small typo
Updated CHANGES
Merge pull request #420 from jwoillez/form_activation

ESO: fixes to retrieve_data() and improvements in login()