Move the parts of the old man/Makefile.in that do not refer to the

Move the parts of the old man/Makefile.in that do not refer to the
Emacs manual here.
(infodir): New variable.
(INFO_TARGETS, info): Use infodir.  Also used by all info targets.
(cc-mode.texi, faq.texi): Update references to source file locations.

Add `basename' versions of all info targets, for convenience when
rebuilding just one manual.
(../etc/GNU): Delete obsolete target.
(.SUFFIXES): Use $(TEXI2DVI) rather than texi2dvi.
(mostlyclean): Add *.op, *.ops.  Move *.aux *.cps *.fns *.kys *.pgs