neutronclient shows low-level logs in console screen

Neutron command lines always display some useless information. This
should be avoided. This commit modifies the default level of console
stream to WARNING.

Closes-bug: #1356735

Change-Id: I997dad9ce3fc3eb795e4e44b27d211fa619c1907
Stop using intersphinx

Remove intersphinx from the docs build as it triggers network calls that
occasionally fail, and we don't really use intersphinx (links other
sphinx documents out on the internet)

This also removes the requirement for internet access during docs build.

This can cause docs jobs to fail if the project errors out on
warnings.

Change-Id: I71e941e2a639641a662a163c682eb86d51de42fb
Related-Bug: #1368910
Merge "Stop using intersphinx"
Merge "neutronclient shows low-level logs in console screen"