Network timeout handling

[fireice-uk]

[2016-11-27 00:10:23] Stratum connection timed out [2016-11-27 00:10:23] Stratum connection interrupted [2016-11-27 00:10:23] Stratum detected new block [2016-11-27 00:10:24] GPU #0: GeForce GTX 1070, 725.35 H/s [2016-11-27 00:10:24] accepted: 782/783 (99.87%), 725.35 H/s (booooo) [2016-11-27 00:10:24] reject reason: Invalid job id [2016-11-27 00:10:43] GPU #0: GeForce GTX 1070, 713.09 H/s

You asked for it so here it is :). "Stratum connection timed out" will be always exactly 2 minutes after our last comms with the pool.