Checking versions and defining macros

[Jason Curl]

Hello,

To achieve my goals, I've borrowed some of the internals of the auto* 
tools (and libtool). I'd like to somehow check the version of the 
autotools during "autoreconf" time and include macros specific to a 
particular version. If I see a version that I haven't tested with, then 
I'd like to print a warning that something needs to be looked at (i.e. 
update my macros). This will allow me especially to upgrade to 
libtool-2.2 and play with it, while knowing it will always work with 1.5.24.

A summary of what I've had to hack:
AC_CHECK_LIB: borrowed from here for the Solaris networking features
AC_CHECK_DECL: Disable printing, to encapsulate in my own scripts
AC_PROG_LD: Would die if it couldn't find LD, rather than allow my 
configure.ac to provide an alternate

Thanks,
Jason.