Merge branch 'master' into staging

diff --cc gnu/local.mk
Simple merge

diff --cc gnu/packages/check.scm
Simple merge

diff --cc gnu/packages/education.scm
Simple merge

diff --cc gnu/packages/gnome.scm
Simple merge

diff --cc gnu/packages/gtk.scm
Simple merge

diff --cc gnu/packages/python-xyz.scm
Simple merge

diff --cc gnu/packages/video.scm
Simple merge