Implement MainIteration() and EventsPending()
Implement MainIteration() and EventsPending()

Resolves #70

yamnikov-oleg/gotk3,pekim/gotk3,pekim/gotk3,andre-hub/gotk3,yamnikov-oleg/gotk3,andre-hub/gotk3,andre-hub/gotk3,gotk3/gotk3,gotk3/gotk3,yamnikov-oleg/gotk3,pekim/gotk3