more idiomatic std features

substrate/native-runtime/Cargo.toml

@@ -9,6 +9,5 @@ runtime-std = { path = "./std", version = "0.1" }
 rustc-hex = "1.0"
 
 [features]
-default = ["with-std"]
-with-std = []
-without-std = ["polkadot-runtime-codec/no-std"]
+default = ["std"]
+std = ["polkadot-runtime-codec/std"]

substrate/native-runtime/std/src/lib.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
-//! The with-std support functions for the runtime.
+//! The std support functions for the runtime.
 
 #[macro_use]
 extern crate environmental;