Include LICENSE-* files into all sub-crates

[ignatenkobrain]

I'm packaging actix-* for Fedora and I noticed that on tarballs from crates.io, there are no LICENSE files. I believe that this is one of legal requirements of Apache-2.0. I think creating symlink in each directory and publishing new version should do the trick.

Thanks!

[fafhrd91]

should be added to all creates