Implement automatic duration updating.
Implement automatic duration updating.

Running time entries duration is now updated auto-magically. Whenever a
model that is running is in memory, it starts the update looping, which
runs until all of the running models have been GCed.

eatskolnikov/mobile,peeedge/mobile,eatskolnikov/mobile,peeedge/mobile,masterrr/mobile,ZhangLeiCharles/mobile,ZhangLeiCharles/mobile,masterrr/mobile,eatskolnikov/mobile