Merge branch 'master' into ng/master

* master:
  tests: fix reference to related tests in some comments
  tests: some enhancements to texinfo tests (from Automake-NG)
  tests: fix reference to sister tests in two heading comments

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --cc t/color-tests.sh
Simple merge

diff --cc t/color-tests2.sh
Simple merge

diff --cc t/remake-deleted-m4-file.sh
Simple merge