Build fails on CentOS due to missing m4 directory and AM_PROG_AR
The m4 directory just needs to exist. Not sure if git will show it if the directory doesn't contain something, which means I may need to check in the files generated in m4 by autoconf.
The AM_PROG_AR variable is not in the version of automake on CentOS 6.x. The fix may be to use an m4 ifdef