Merge branch 'master' into ng/master

Merge branch 'master' into ng/master

* master:
  fixup: copyright yars in two recent tests
  obsolete: fixup: don't use AU_DEFUN where AC_DEFUN is required
  obsolete: better error message if AM_PROG_MKDIR_P is used
  NEWS: document removal of AM_PROG_MKDIR_P macro
  NEWS: minor fixup
  obsolete: better error message if AM_PROG_CC_STDC is used
  obsolete: better error message if AM_CONFIG_HEADER is used
  sync: update files from upstream with "make fetch"
  tests: better names for temporary configure.ac files

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