remove autogen.sh, confusing and pointless
update AUTHORS from git history
clean up def path defs a bit
clean up configure help output a bit
docs autotools refactor + simple path templating

Re-centralized the docs to make autotools stuff simpler

Got rid of pod->txt for gdnsd_manual, can just be written
in text.

Stopped installing pod/txt copies of the installed manpages.

Added a sed-based system for templating the configured
default filesystem paths into the manpages, so the docs
can be clearer.  The templated directory variables look like:
@GDNSD_DEFPATH_RUN@

Made perl + pod2man required for build so that we don't
have to ship intermediate outputs for the new templating
in tarballs and so that the automake rules are simpler.
template paths in existing docs