update to recent rust changes: * -> *const [need lifetime fix]

Subj. There's still a problem through:

    % make
    mkdir -p build
    rustc -O --cfg ndebug --dep-info build/libfuse.d --out-dir build/ src/lib.rs
    src/reply.rs:125:11: 125:26 error: cannot infer an appropriate lifetime due to conflicting requirements
    src/reply.rs:125 			sender(Vec::from_slice(headerbytes).append(bytes).as_slice());
                                       ^~~~~~~~~~~~~~~
    src/reply.rs:115:51: 127:3 note: first, the lifetime cannot outlive the anonymous lifetime #3 defined on the block at 115:50...
    src/reply.rs:115 	fn send (&mut self, err: c_int, bytes: &[&[u8]]) {
    src/reply.rs:116 		assert!(self.sender.is_some());
    src/reply.rs:117 		let len = bytes.iter().fold(0, |l, b| { l +  b.len()});
    src/reply.rs:118 		let header = fuse_out_header {
    src/reply.rs:119 			len: (mem::size_of::<fuse_out_header>() + len) as u32,
    src/reply.rs:120 			error: -err,
                     ...
    src/reply.rs:125:47: 125:52 note: ...so that expression is assignable (expected `&[&[u8]]` but found `&[&[u8]]`)
    src/reply.rs:125 			sender(Vec::from_slice(headerbytes).append(bytes).as_slice());
                                                                           ^~~~~
    src/reply.rs:123:35: 126:4 note: but, the lifetime must be valid for an anonymous lifetime defined on the block at 123:34...
    src/reply.rs:123 		as_bytes(&header, |headerbytes| {
    src/reply.rs:124 			let sender = self.sender.take_unwrap();
    src/reply.rs:125 			sender(Vec::from_slice(headerbytes).append(bytes).as_slice());
    src/reply.rs:126 		});
    src/reply.rs:125:11: 125:26 note: ...so that type matches impl (expected `&[u8]` but found `&[u8]`)
    src/reply.rs:125 			sender(Vec::from_slice(headerbytes).append(bytes).as_slice());

I don't know about lifetimes much, so I have no idea how to make it work.