Merge branch 'release-3.1.0'

doc/html/_sources/users.txt

doc/html/_static/basic.css

doc/html/_static/comment-bright.png

doc/html/_static/comment-close.png

doc/html/_static/comment.png

doc/html/_static/doctools.js

doc/html/_static/documentation_options.js

doc/html/_static/down-pressed.png

doc/html/_static/down.png

doc/html/_static/file.png

doc/html/_static/jquery-1.11.1.js

doc/html/_static/jquery.js

doc/html/_static/minus.png

doc/html/_static/plus.png

doc/html/_static/searchtools.js

doc/html/_static/up-pressed.png

doc/html/_static/up.png

doc/html/_static/websupport.js

doc/html/actions/index.html

doc/html/actions/index_dev.html