std: Stabilize last bits of io::Error

This commit stabilizes a few remaining bits of the `io::Error` type:

* The `Error::new` method is now stable. The last `detail` parameter was removed
  and the second `desc` parameter was generalized to `E: Into<Box<Error>>` to
  allow creating an I/O error from any form of error. Currently there is no form
  of downcasting, but this will be added in time.

* An implementation of `From<&str> for Box<Error>` was added to liballoc to
  allow construction of errors from raw strings.

* The `Error::raw_os_error` method was stabilized as-is.

* Trait impls for `Clone`, `Eq`, and `PartialEq` were removed from `Error` as it
  is not possible to use them with trait objects.

This is a breaking change due to the modification of the `new` method as well as
the removal of the trait implementations for the `Error` type.

[breaking-change]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/net/mod.rs b/src/libstd/net/mod.rs
index ee57300765e..a152b98822a 100644
--- a/src/libstd/net/mod.rs
+++ b/src/libstd/net/mod.rs
@@ -72,7 +72,7 @@ fn each_addr<A: ToSocketAddrs, F, T>(addr: A, mut f: F) -> io::Result<T>
     }
     Err(last_err.unwrap_or_else(|| {
         Error::new(ErrorKind::InvalidInput,
-                   "could not resolve to any addresses", None)
+                   "could not resolve to any addresses")
     }))
 }