6.0.0

I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.

packages/babel-plugin-transform-es2015-parameters/src/destructuring.js

@@ -0,0 +1,24 @@
+import * as t from "babel-types";
+
+export let visitor = {
+  Function(path) {
+    let params: Array = path.get("params");
+    
+    for (let i = 0; i < params.length; i++) {
+      let param = params[i];
+      if (param.isArrayPattern() || param.isObjectPattern()) {
+        let uid = path.scope.generateUidIdentifier("ref");
+
+        let declar = t.variableDeclaration("let", [
+          t.variableDeclarator(param.node, uid)
+        ]);
+        declar._blockHoist = params.length - i;
+
+        path.ensureBlock();
+        path.get("body").unshiftContainer("body", declar);
+
+        param.replaceWith(uid);
+      }
+    }
+  }
+};