build fix, add .h2m includes to the dist

The man pages could never be re-built from within distdir. Because
of that pattern rule we never got an error.
bldchn, remove unused include from help2man command line
Merge branch 'bld/fix-dist-man' into next

* bld/fix-dist-man:
  bldchn, remove unused include from help2man command line
  build fix, add .h2m includes to the dist