Don't call epoll_wait/kevent if there are no old operations (where old means

added prior to the last epoll_wait/kevent call) needing to be demultiplexed.


[SVN r42755]

libs/asio

@@ -1 +1 @@
-Subproject commit 66e7e8235b63a3f28a19111fdc7436f1db61e5d5
+Subproject commit d02ff9fd317abc2ca4e8f2d45c3b37b47c4ce0ff