Simplify Beast:

* Remove asio HTTP classes
 * Remove beast::File, beast::String, beast::Stream, beast::Array,
   beast::MemoryBlock, beast::CriticalSection and other unused
   classes.
 * Remove unused platform-specific code.
 * Reduce Beast custom assert and debugging helper macros.

beast/insight/impl/StatsDCollector.cpp

@@ -218,7 +218,7 @@ private:
         }
 
         // VFALCO TODO IPv6 support
-        bassertfalse;
+        assert(false);
         return boost::asio::ip::udp::endpoint (
             boost::asio::ip::address_v6 (), 0);
     }