maint: write-file-hooks -> before-save-hook
write-file-hooks is obsolete since Emacs 22.1 (released June 2007) and
it's time to use the recommended replacement.
Problem reported by Glenn Morris in:
https://lists.gnu.org/r/bug-gnulib/2018-03/msg00008.html
* contrib/tap-driver.pl, lib/compile, lib/depcomp, lib/install-sh:
* lib/mdate-sh, lib/missing, lib/mkinstalldirs, lib/py-compile:
* lib/tap-driver.sh, lib/test-driver, lib/ylwrap:
Update hook usage for files where Automake is the canonical source.