Add support for configure --enable-verbose-makecmds

Add support for configure --enable-verbose-makecmds

Some people don't want to see the concise "kernel-style" make output.
This configure option allows build engines that want to see the full
set of commands executed by the makefile to get what they want.  Most
people will find this more distracting than useful, unless they need
to debug the Makefiles.

(It is not necessary to rerun configure to enable this verbose make
output temprarily; if a developer wants to do a quick debug of a
directory's makefile, he or she can simply edit the definition of the
$(E) and $(Q) variables in the Makefile; instructions can be found in
the MCONFIG file which is included in at the beginning of every
Makefile.)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>