build: improve silencing of automake build system In this change, we continue the silencing of the automake build system that has been started in commit v1.11-642-g17542c3, but which has been left incomplete there for an (absent-mindness) mistake. * Makefile.am (INSTALL): Silence the recipe. (automake, aclocal): Likewise, and improve them a little since we are at it. * lib/Automake/Makefile.am (Config.pm): Likewise.