Merge branch 'master' into testsuite-work

Merge branch 'master' into testsuite-work

Commits merged from master:
 - tests: various minor tweakings, mostly related to AM_PROG_AR
 - maint-mode: fix botched configure messages
 - fix: regenerate Makefiles
 - tests: few improvements to some `ar-lib' related tests
 - info: allow user to inhibit creation/update of '${infodir}/dir'
 - warnings: new 'extra-portability' category, for AM_PROG_AR
 - ar-lib: new 'AM_PROG_AR' macro, triggering the 'ar-lib' script

Extra testsuite adjustments:
* tests/instspc.tap: Adjust to new portability requirements
due to the new AM_PROG_AR macro.
* tests/lex-lib.test: Likewise.
* tests/extra-portability2.test: Use `$am_original_AUTOMAKE'
instead of the obsolete `$original_AUTOMAKE'.
* tests/list-of-tests.mk: Update.