Use rsync instead of copymitter for copy

[ericfranz]

This commit includes an intentional regression in functionality, where progress of copy is no longer shared with the user.

A replacement of #197 and a less risky stepping stone to the preferred #202

[ericfranz]

This appears to solve the lustre problem. Errors are reported but are not that helpful. For example, this is the error I get when I try to copy a directory whose permissions are 000:

With e8bd28eb6ad55c834e29b86aa6ca6beb3b0cbb98 we get a message like this:

But the code to enable this is ugly and I have not thoroughly tested it. I'm assuming q is a valid argument for all versions of rsync too.