tiny coding standard fix in 'task.py'
(cherry picked from commit 8f121f542f7588243a301bb3e1651d310f008297)
created and used module -- ``timeout_delay`` (instead of ``yieldpoints``)
(cherry picked from commit 1ed174fb13be6290ea64f02e6c0a58e58e535ab0)
erasing ``sys.exc_info()`` from code
(cherry picked from commit 6bca9f37d20f9a1d660b6e5ac3d4321a6b0df7f0)
fixup! erasing ``sys.exc_info()`` from code
(cherry picked from commit 70a204192d26e417e3819815e539ef4acfc0e7cb)