Rogue V5: remove troublesome automatic platform detection. configure.ac used AC_CANONICAL_SYSTEM to guess the GNU system description triplets. The target description was substituted into the Makefile and formatted into the filename for the binary distribution tarball. But 'target' is only intended for cross-compilers. 'host_os' might have been a better choice. The tarball filename can still be changed manually, by running make with an argument of 'DESTSYS=systemname'. Cross-compiling may be more difficult now, but I am not certain that it worked properly previously, and due to pending autoconf changes, it was likely to break anyway. The top-level config.guess and config.sub are no longer needed, but they may reappear if better support for cross-compilation is added.