Files module: Allow touch on hardlinks

I recently ran into an issue where an Ansible playbook failed to touch a file, with the error: "Cannot touch other than files and directories"

After a bit of investigation, I realized that the file was a hard link. I see no reason why `touch` shouldn't work against hard links, so I made the change.

I've also made an integration test, but that's in the top `ansible` git submodule. I'll issue a separate PR for the test against that project.