MoveWrapper::move()

Summary: sugar providing `foo.move()` instead of `std::move(*foo)`.

Test Plan: Inspection. Using it in another diff.

Reviewed By: yfeldblum@fb.com, hannesr@fb.com

Subscribers: trunkagent, exa, folly-diffs@, yfeldblum

FB internal diff: D1882208

Signature: t1:1882208:1425331389:a9c09ad2739838c829e2afdad64e985810154226

folly/MoveWrapper.h

@@ -54,6 +54,9 @@ class MoveWrapper {
   const T* operator->() const { return &value; }
         T* operator->()       { return &value; }
 
+  /// move the value out (sugar for std::move(*moveWrapper))
+  T&& move() { return std::move(value); }
+
   // If you want these you're probably doing it wrong, though they'd be
   // easy enough to implement
   MoveWrapper& operator=(MoveWrapper const&) = delete;