Utilize fewer reexports

In regards to:

https://github.com/rust-lang/rust/issues/19253#issuecomment-64836729

This commit:

* Changes the #deriving code so that it generates code that utilizes fewer
  reexports (in particur Option::* and Result::*), which is necessary to
  remove those reexports in the future
* Changes other areas of the codebase so that fewer reexports are utilized

src/libstd/failure.rs

@@ -16,8 +16,9 @@ use cell::RefCell;
 use fmt;
 use io::{Writer, IoResult};
 use kinds::Send;
-use option::{Some, None, Option};
-use result::Ok;
+use option::Option;
+use option::Option::{Some, None};
+use result::Result::Ok;
 use rt::backtrace;
 use rustrt::{Stderr, Stdio};
 use rustrt::local::Local;