Fix for multicast propagation -- supernodes must always keep propagating. Also fix mac-tap build on new version of Xcode CL tools. Must use old llvm-g++ instead of clang for i686 -mkernel.

node/Utils.hpp

@@ -572,7 +572,7 @@ public:
 		char *end = dest + len;
 		while ((*dest++ = *src++)) {
 			if (dest == end) {
-				--dest = (char)0;
+				*(--dest) = (char)0;
 				return false;
 			}
 		}