Autoconf stuff

GNU autoconf is a program designed to detect the features available on a particular platform. It can be used to determine the compilers available on a platform, what the CPU and operating system are, what flags the compilers take, and as many other things as m4 macros can be written to cover.

Autoconf is configured by a file configure.in which autoconf turns into a file called configure (which should never be editted by hand). The cactus configuration includes the resulting configure file and this should not need to be regenerated by other than flesh-maintainers.

When the configure script is run it takes the files config.h.in, make.config.defn.in, make.config.rules.in, and make.config.deps.in and generates new files in the configuration's config-data subdirectory with the same names with the .in stripped off. The configure script replaces certain parts of these files with the values it has detected for this architecture.

In addition configure runs the configure.pl perl script to do things which can only be done easily by perl.