merge *SliceExt traits, use assoc types in SliceExt, Raw[Mut]Ptr

src/libstd/io/mod.rs

@@ -1919,7 +1919,7 @@ impl fmt::Show for FilePermission {
 mod tests {
     use self::BadReaderBehavior::*;
     use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput, Writer};
-    use prelude::{Ok, Vec, Buffer, CloneSliceExt};
+    use prelude::{Ok, Vec, Buffer, SliceExt};
     use uint;
 
     #[deriving(Clone, PartialEq, Show)]