Changes to remedy close_waits when failover nodes are taken out of rotation.

Added support for monitoring sync pulls via a single ping to determine host health. Monitoring can (does) occur when hosts take regular traffic however failover nodes do not take any traffic and need some monitoring (hence ping).
Close connections in all scenarios other than "timeout".
Merge branch 'master' of https://github.com/cporter71/dyno into cp-fork-master