autoconf warningsfrom mac build

[pieper]

These were not fatal issues, but may be worth addressing for cleanliness.

 % autoreconf -i
glibtoolize: putting auxiliary files in '.'.
glibtoolize: copying file './ltmain.sh'
glibtoolize: Consider adding 'AC_CONFIG_MACRO_DIRS([m4])' to configure.ac,
glibtoolize: and rerunning glibtoolize and aclocal.
glibtoolize: Consider adding '-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
configure.ac:7: warning: The macro `AC_CONFIG_HEADER' is obsolete.
configure.ac:7: You should run autoupdate.
./lib/autoconf/status.m4:719: AC_CONFIG_HEADER is expanded from...
configure.ac:7: the top level
configure.ac:18: warning: The macro `AC_PROG_CC_C99' is obsolete.
configure.ac:18: You should run autoupdate.
./lib/autoconf/c.m4:1659: AC_PROG_CC_C99 is expanded from...
configure.ac:18: the top level
configure.ac:16: installing './compile'
configure.ac:12: installing './config.guess'
configure.ac:12: installing './config.sub'
configure.ac:9: installing './install-sh'
configure.ac:9: installing './missing'
Makefile.am: installing './depcomp'
parallel-tests: installing './test-driver'

[hackermd]

Addressed via 342bd924c093929f2755f188a1a850fb432d7755