configure: Fix warnings on CentOS and bump the minimum autoconf version
* configure.ac: Bump the minimum version to 2.60 as needed by
AC_USE_SYSTEM_EXTENSIONS. AC 2.60 is nearly 10 years old, note. Add
AC_PROG_RANLIB, for when --disable-shared is used.
There are other warnings on, e.g., CentOS 6.7 with 2.63, but they
don't go away if the suggestion to add AC_SYSTEM_EXTENSIONS is
followed. This warning doesn't occur on Fedora with AC 2.69.
Note: autoconf (and other auto*) should only be needed on developer
machines building direct from git. Other systems should be using the
'make dist' tarballs, with a ready-made build system, that does not
need auto* intalled.
1 file changed