Created BindableListIterator for BindableListWrapper.

BindableListIterator supports add, remove, and set operations in a way
that calls handlers for the bound ListWidget.
Fixed scheduling bug in errai-otec.

Now when OTServerEngine interrupts housekeeper thread immediately.
Otherwise thread has unnecessary 10 second pause.
Created BindableListIterator for BindableListWrapper.

BindableListIterator supports add, remove, and set operations in a way
that calls handlers for the bound ListWidget.
Merge branch '2.4'