libcc1: delete copy constructor and assignment operators

Change libcc1 to use "= delete" for the copy constructor and
assignment operator, rather than the old approach of private methods
that are nowhere defined.

libcc1

	* rpc.hh (argument_wrapper): Use delete for copy constructor.
	* connection.hh (class connection): Use delete for copy
	constructor.
	* callbacks.hh (class callbacks): Use delete for copy constructor.