cmd: Copying disallowed to/from special device files like con and nul.

The CLI copy command disallows copying files from/to special device files like con and nul. Windows does allow this for the copy command.

For example, if entering this on windows:
copy con nul
The copy process would ask the user for input until Control-Z or Control-C was pressed. When pressing Control-C windows would fail the Input/Output operation.

When entering the same command on ReactOS it gives the error:
ERROR_INVALID_NAME - The filename, directory name, or volume label syntax is incorrect.

KVM Version: QEMU PC emulator version 0.9.1 (kvm-62)
ReactOS Version: 0.3.5 Installation/Boot Image