merge from master

diff --cc lisp/gnus/gnus-group.el
Simple merge

diff --cc lisp/gnus/gnus-msg.el
Simple merge

diff --cc lisp/gnus/gnus-registry.el
Simple merge

diff --cc lisp/gnus/gnus-srvr.el
Simple merge

diff --cc lisp/gnus/gnus-sum.el
Simple merge

diff --cc lisp/gnus/gnus.el
Simple merge

diff --cc lisp/gnus/nnimap.el
Simple merge

diff --cc lisp/gnus/nnir.el
Simple merge

diff --cc test/manual/image-size-tests.el
Simple merge