Finally, we are able to identify the builds more accurately. Now we check
if commit-id (cogito tool) is available and pass the output to vernum.c
compilation which then exports it as a build_id string.
The first line of --version is now a bit long, we should probably move the
build date to a second indented line or something.
All objects defining $(OBJS) will get them and *.a deleted during
make clean.
The all, clean and install rules now implicitly imply their -recursive
counterparts - those will just do nothing in case of $(SUBDIRS) not
defined, so that's ok.
The root makefile is converted as well as some leaf Makefiles. This
also brings in the required infrastructure and adjusts configure.in
appropriately.
I converted only makefiles containing no configurable stuff, since
that'll require more consideration yet.
