Eliminate warnings in 4.02.0

Unfortunately, this won't compile with 4.01.0, but the changes are
minor.
Remove dependent projects

Now that all of our dependent projects are available in opam, remove
the source here and reference them properly as packages.
Ignore "test-pool" directory

It is useful to have a 'test-pool' directory.  However, ocamlbuild
likes to descend directories, even symlinks, to look for hygeine
issues.  With a large pool, this can add quite a delay to the initial
build time.

Add a line to the _tags file to tell it to not traverse this directory
at all.
Add some Fedora instructions to the README