Update to build on Xcode 6.0: fix Boost intrusive_ptr scoping issue

indra/llcommon/llrefcount.h

@@ -151,8 +151,8 @@ private:
  * intrusive pointer support for LLThreadSafeRefCount
  * this allows you to use boost::intrusive_ptr with any LLThreadSafeRefCount-derived type
  */
-namespace boost
-{
+// namespace boost
+// {
 	inline void intrusive_ptr_add_ref(LLThreadSafeRefCount* p) 
 	{
 		p->ref();
@@ -172,7 +172,7 @@ namespace boost
 	{
 		p->unref(); 
 	}
-};
+//};