m4: rename all macros that start with AC_ to start with another prefix
-Consider using an autoconf test and rename wrapper to make mv work
-properly (by unlinking a) in cases like this:
- : > a; ln a b; mv a b
-Reported by Ed Avis: http://article.gmane.org/gmane.comp.gnu.fileutils.bugs/686
-
document that `true --version' can fail, e.g., like this:
./true --version >&-
./true: write error: Bad file number