autoconf: possibly undefined macros

[dvogel]

Following the directions in the README, I ran into this set of errors:

configure.ac:3: error: possibly undefined macro: AM_INIT_AUTOMAKE
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.ac:26: error: possibly undefined macro: AC_DISABLE_SHARED
configure.ac:27: error: possibly undefined macro: AC_PROG_LIBTOOL

I was able to satisfy autoconf by running libtoolize:

> libtoolize 
libtoolize: putting auxiliary files in `.'.
libtoolize: linking file `./ltmain.sh'
libtoolize: putting macros in AC_CONFIG_MACRO_DIR, `m4'.
libtoolize: linking file `m4/libtool.m4'
libtoolize: linking file `m4/ltoptions.m4'
libtoolize: linking file `m4/ltsugar.m4'
libtoolize: linking file `m4/ltversion.m4'
libtoolize: linking file `m4/lt~obsolete.m4'

Would you prefer a PR with those files committed or with that step added to the directions in the README?

[unnikrishnanta]

On a mac,
brew install libtool
and running libtool worked for me.