Convert unstable to the requested features

examples/extract.rs

@@ -1,4 +1,4 @@
-#![allow(unstable)]
+#![feature(path, io, os)]
 
 extern crate zip;
 

examples/extract_lorem.rs

@@ -1,4 +1,4 @@
-#![allow(unstable)]
+#![feature(os, path, io)]
 
 extern crate zip;
 

examples/write_sample.rs

@@ -1,4 +1,4 @@
-#![allow(unstable)]
+#![feature(io, os, path)]
 
 extern crate zip;
 

src/lib.rs

@@ -2,7 +2,8 @@
 
 #![feature(unsafe_destructor)]
 #![warn(missing_docs)]
-#![allow(unstable)]
+
+#![feature(core, collections, io, std_misc)]
 
 extern crate time;
 extern crate flate2;