Makefiles in *-only copy the object file module is created from into the
parent directory but do not delete them on "make clean". Clean these files
up in "clean" target of top level makefile.
Add a top level makefile to make common tasks easier. Supported targets:
make - build modules
make install - install modules (honors DESTDIR)
make clean - clean up
make tarballs - create source tarballs from current HEAD
Note: "make tarballs" uses "git archive" so that it only works in a local
copy of the git repository, not in a directory created by unpacking
a tarball.
Add *.tar to .gitignore to hide tarballs created by "make tarballs".
Michal Kubecek