Cleanup unused Beast bits and pieces:

This cleanup does not remove Boost.Beast code, but old-style Beast
which is no longer relevant or helpful.

src/ripple/app/main/Main.cpp

@@ -37,7 +37,6 @@
 #include <ripple/protocol/BuildInfo.h>
 #include <ripple/beast/clock/basic_seconds_clock.h>
 #include <ripple/beast/core/CurrentThreadName.h>
-#include <ripple/beast/utility/Debug.h>
 
 #include <beast/unit_test/dstream.hpp>
 #include <beast/unit_test/global_suites.hpp>
@@ -766,26 +765,6 @@ int main (int argc, char** argv)
         "GCC version 5.1.0 or later is required to compile rippled.");
 #endif
 
-    //
-    // These debug heap calls do nothing in release or non Visual Studio builds.
-    //
-
-    // Checks the heap at every allocation and deallocation (slow).
-    //
-    //beast::Debug::setAlwaysCheckHeap (false);
-
-    // Keeps freed memory blocks and fills them with a guard value.
-    //
-    //beast::Debug::setHeapDelayedFree (false);
-
-    // At exit, reports all memory blocks which have not been freed.
-    //
-#if RIPPLE_DUMP_LEAKS_ON_EXIT
-    beast::Debug::setHeapReportLeaks (true);
-#else
-    beast::Debug::setHeapReportLeaks (false);
-#endif
-
     atexit(&google::protobuf::ShutdownProtobufLibrary);
 
     std::set_terminate(ripple::terminateHandler);