With GNU make, MFLAGS is not needed

With GNU make, MFLAGS is not needed

* Makefile.in (CC, CFLAGS, LDFLAGS, CPPFLAGS, abs_top_srcdir):
Remove, no longer used.
(lib, lib-src, lisp, nt, src, blessmail, install-arch-dep)
(install-nt, install-strip, uninstall, uninstall-nt)
(mostlyclean, clean, distclean, bootstrap-clean)
(maintainer-clean, extraclean, TAGS, tags, check, $(DOCS)):
($(INSTALL_DOC), $(UNINSTALL_DOC), info, bootstrap, check-declare):
GNU make automatically passes command-line arguments to sub-makes.

* admin/unidata/Makefile.in (${DSTDIR}/charprop.el):
GNU make automatically passes command-line arguments to sub-makes.

* lib-src/Makefile.in (../lib/libgnu.a):
GNU make automatically passes command-line arguments to sub-makes.

* lisp/Makefile.in ($(lisp)/cus-load.el, $(lisp)/finder-inf.el)
(autoloads, $(lisp)/subdirs.el, compile-main, leim, semantic, compile)
(compile-always): GNU make automatically passes
command-line arguments to sub-makes.

* lwlib/Makefile.in ($(globals_h)):
GNU make automatically passes command-line arguments to sub-makes.

* src/Makefile.in ($(leimdir)/leim-list.el, $(srcdir)/macuvs.h)
($(lispsource)/international/charprop.el)
($(libsrc)/make-docfile$(EXEEXT), $(lwlibdir)/liblw.a)
($(oldXMenudir)/libXMenu11.a, ns-app, .el.elc)
($(lispsource)/loaddefs.el, bootstrap-emacs$(EXEEXT)):
GNU make automatically passes command-line arguments to sub-makes.

* test/automated/Makefile.in (compile-main):
GNU make automatically passes command-line arguments to sub-makes.