Fixes for copy_to and move_to methods

[robrwo]

• The destination for copy_to and move_to is stringified
• Updated POD about to clarify the behaviour of these methods
• Whitespace cleanup

[kenahoo]

Thanks, looks good, I merged it in. Is there a case where this fixes a bug? Would be nice to add a regression test for it to show why it's necessary.

[robrwo]

I didn't actually run across bugs, but it occurred to me that if the source needed to be stringified, then so did the destination.