[2.3.x] [2.3.x] Alternate fix for https://java.net/jira/browse/GRIZZLY-1594 (ReadHandler callbacks should not be performed in I/O thread.)
  (Thanks Alexey)
[2.3.x] Fix a reversion in some previous changes.
[2.3.x] + fix SameThreadIOStrategy suspend/setManualIOEventControl, allow to disableIOEvent just once per context life-cycle
[2.3.x] + Minor update for the latest fix for https://java.net/jira/browse/GRIZZLY-1594 (ReadHandler callbacks should not be performed in I/O thread.)