+20121006
+ + improve CF_GCC_VERSION to work around Debian's customization of gcc
+ --version message.
+ + improve configure macros as done in byacc:
+ + drop 2.13 compatibility; use 2.52.xxxx version only since EMX port
+ has used that for a while.
+ + add 3rd parameter to AC_DEFINE's to allow autoheader to run, i.e.,
+ for experimental use.
+ + remove unused configure macros.
+ + modify configure script and makefiles to quiet new autoconf warning
+ for LIBS_TO_MAKE variable.
+ + modify configure script to show $PATH_SEPARATOR variable.
+ + update config.guess, config.sub
+