Fix SSH oddness by passing arguments directly through to SSH as-is

Also, added "LogLevel=quiet" to suppress the fun warning that was printed every time we run "boot2docker ssh ...".

Fixes #165
Closes #135 (since we can now do `boot2docker ssh -v ...` and it works as you'd expect, which is useful separately from `boot2docker -v ssh ...` which prints the exact command it's running)