Merge branch 'master' into staging

diff --cc gnu/local.mk
Simple merge

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

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

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

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

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

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