WIP: nrao archive query - TAP only so far, based on ALMA

(additional commit message was just debug notes and should be ignored)

add back tapsql stuff

remove alma stuff from nrao

add nrao obscore thing

Adapt region queries to work with NRAO TAP service

add tapsql.py for nrao, updates to data columns supported by NRAO TAP

fix imports

implemented data retrieval code

flush

add VLA handling

fix the wait-until-done step

flex fixes

astroquery/nrao/__init__.py

@@ -0,0 +1,44 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
+"""
+NRAO Archive service.
+"""
+from astropy import config as _config
+
+
+# list the URLs here separately so they can be used in tests.
+_url_list = ['https://data.nrao.edu'
+             ]
+
+tap_urls = ['https://data-query.nrao.edu/']
+
+auth_urls = ['data.nrao.edu']
+
+
+class Conf(_config.ConfigNamespace):
+    """
+    Configuration parameters for `astroquery.nrao`.
+    """
+
+    timeout = _config.ConfigItem(60, "Timeout in seconds.")
+
+    archive_url = _config.ConfigItem(
+        _url_list,
+        'The NRAO Archive mirror to use.')
+
+    auth_url = _config.ConfigItem(
+        auth_urls,
+        'NRAO Central Authentication Service URLs'
+    )
+
+    username = _config.ConfigItem(
+        "",
+        'Optional default username for NRAO archive.')
+
+
+conf = Conf()
+
+from .core import Nrao, NraoClass, NRAO_BANDS
+
+__all__ = ['Nrao', 'NraoClass',
+           'Conf', 'conf',
+           ]