Merge branch 'master' into ng/master

Merge branch 'master' into ng/master

* master:
  tests: fix spurious failures caused by uses of 'configure.in'
  install-mans: avoid spurious failure with NetBSD make
  install: don't create empty dirs when an empty 'foo_PRIMARY' is used
  aclocal: remove a couple of useless imports
  aclocal: create local directory where to install m4 files
  python: avoid failures due to $(am__py_compile) being undefined
  python: expose automake bug#10995
  tests: one more use of 'unindent' function
  tests: remove redundant 'set -e' calls
  tests: fix spurious failure with older m4
  tests: avoid spurious failures in get-sysconf.test
  scripts: bump the depcomp scriptversion
  sync: some auxiliary files synced from upstream
  coverage: an empty foo_PRIMARY should create directory $(foodir)
  coverage: make sure am__py_compile is defined when needed
  coverage: expose automake bug#10997
  coverage: expose automake bug#10975
  getopt: relax version requirement for perl