Remove Object.prototype.mixin and Function.prototype.curry

They are not used that much and I really want to keep
proto minimal.

lib/proto.js

@@ -21,8 +21,6 @@ SOFTWARE.
 */
 
 var proto = Object.prototype;
-var func_proto = Function.prototype;
-var arr_proto = Array.prototype;
 
 // Implements a forEach much like the one for Array.prototype.forEach, but for
 // any object.
@@ -51,29 +49,3 @@ if (typeof proto.map !== 'function') {
     return accum;
   }});
 }
-
-// Implements a shallow copy onto the current object.
-if (typeof proto.mixin !== 'function') {
-  Object.defineProperty(proto, "mixin", {value: function (obj) {
-    var keys = Object.keys(obj);
-    var length = keys.length;
-    for (var i = 0; i < length; i++) {
-      var key = keys[i];
-      this[key] = obj[key];
-    }
-    return this;
-  }});
-}
-
-// Implements a function curry function.  This allows you to call part of a
-// function later.
-if (typeof func_proto.curry !== 'function') {
-  Object.defineProperty(func_proto, "curry", {value: function () {
-    var fn = this;
-    var first = arr_proto.slice.call(arguments);
-    return function () {
-      return fn.apply(this, first.concat(arr_proto.slice.call(arguments)));
-    };
-  }});
-}
-