chore, move auxiliary stuff to build-aux/
chore, adapt git ignore list
chore, use modern automake flags
chore, up to latest sxe-compiler.m4
chore, use sxe-compiler m4 macros for C flags
chore, import yuck chain
chore, go back to AC_INIT version numbers
use yuck version numbers

Also kill former git-version-gen script.
major, kick gengetopt generators and use yuck instead
Merge branch 'feat/go-yuck' into bld/dist

* feat/go-yuck:
  major, kick gengetopt generators and use yuck instead
  use yuck version numbers
  chore, go back to AC_INIT version numbers
  chore, import yuck chain
fix, PEBKAC, there is no README.md to be distributed
Merge branch 'bld/dist'

* bld/dist:
  fix, PEBKAC, there is no README.md to be distributed
  major, kick gengetopt generators and use yuck instead
  use yuck version numbers
  chore, go back to AC_INIT version numbers
  chore, import yuck chain
  chore, use sxe-compiler m4 macros for C flags
  chore, up to latest sxe-compiler.m4
  chore, use modern automake flags
  chore, adapt git ignore list
  chore, move auxiliary stuff to build-aux/