get rid of autogen.sh and bootstrap.sh
always build core docs
we don't need the C++ compiler
we don't need the C preprocessor on its own
use AC_LANG_SOURCE to silence warnings from autoconf
AC_HEADER_STDC is officially obsolescent
move the rtnetlink.h/C99 check and always fail configure if it fails
require C99
remove some unneeded tests
remove some more unneeded checks
forgot to pull the publish_no_reverse change to the example.