Merge branch 'master' into ng/master

Merge branch 'master' into ng/master

* master:
  news: Automake 1.13 will require Autoconf >= 2.65
  news: put planned future backward-incompatibilities on top
  readme: update INSTALL to latest version from Autoconf
  sync: some auxiliary files synced from upstream
  hacking: copyright notices must be updated before releasing
  color-tests: coloring can be forced on non-ANSI terminals as well
  tests: root can write on files without write perms; cater for this
  tests: require lex, not yacc, in a lex test case
  AM_PROG_MKDIR_P: remove as obsolete
  AM_PROG_MKDIR_P: deprecate, to be removed in Automake 1.13
  maint: fix a comment typo

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