Don't hard-code the list of info files in the top-level Makefile

Don't hard-code the list of info files in the top-level Makefile

The sed '/ing directory/d' piece is to remove the annoying
"entering/leaving directory" messages that GNU make insists on
printing when called recursively.  --no-print-directory isn't portable.

* Makefile.in (INFO_FILES): Remove variable.
(INFO_NONMISC): New variable.
(install-arch-indep, uninstall): Don't use $INFO_FILES.

* doc/misc/Makefile.in (echo-info): New phony target, used by top-level.