Make the timer management scale better across multicore
Author: Ian Lynagh <email@example.com> Date: Sat Jun 8 20:19:59 2013 +0100 IO manager: Edit the timeout queue directly, rather than using an edit list Fixes #7653.
undid an optimization to the management of timeouts (to fix a bug, which is good). We should check how much this hurt performance, but it might be better to rewrite the timeout management altogether. The current scheme scales poorly to several cores. We should probably have one priority queue per core and use an efficient mutable data structure.