end plugin/module naming schizophrenia
  fixup shell code and m4 macro comments
  cmakelists.txt included in EXTRA_DIST


BUILD/SETUP.sh:
  change module -> plugin
config/ac-macros/plugins.m4:
  change module -> plugin
  rename some macros
  fixup comments
  alter shell code to use similar 'test "X$var" = Xfoo"' which autoconf generates
configure.in:
  change module -> plugin
  move plugin mandatory declarations near rest of plugin declaration
storage/archive/Makefile.am:
  cmakelists.txt needed in EXTRA_DIST
storage/blackhole/Makefile.am:
  cmakelists.txt needed in EXTRA_DIST
storage/csv/Makefile.am:
  cmakelists.txt needed in EXTRA_DIST
storage/example/Makefile.am:
  cmakelists.txt needed in EXTRA_DIST