General refactoring, using C++11

* Remove broken RecycledObjectPool

* Fix beast::ServiceQueue using List instead of LockFreeStack

* Add class semaphore, fixes broken Semaphore

* Move crytpo module files to new beast directory

* Use c++11 replacements for boost and beast types:
  - std::atomic instead of beast::Atomic
  - std::function instead of boost::function, beast::function
  - std::unique_ptr instead of beast::ScopedPointer
  - std::shared_ptr instead of boost::shared_ptr

* Remove modules:
  - beast_db
  - beast_crypto
  - beast_extras

* Remove unnecessary classes:
  - AbstractFifo
  - AddConst
  - AtomicCounter
  - AtomicFlag
  - AtomicPointer
  - AtomicState
  - CopyConst
  - Expression
  - ForwardList
  - IfCond
  - Interval
  - IntrusiveArray
  - KeyvaDB
  - PointerToOther
  - PointerTraits
  - RemoveConst
  - RemoveConstVolatile
  - RemoveReference
  - RemoveVolatile
  - SharedObjectArray
  - SingleThreadedSharedObject
  - SophiaDB factory
  - SortedSet
  - WeakReference
  - beast::unique_ptr

src/ripple/validators/impl/SourceStrings.cpp

@@ -75,10 +75,7 @@ private:
 SourceStrings* SourceStrings::New (
     String name, StringArray const& strings)
 {
-    ScopedPointer <SourceStrings> object (
-        new SourceStringsImp (name, strings));
-
-    return object.release ();
+    return new SourceStringsImp (name, strings);
 }
 
 }