Avoid spurious notifications about changes to activeStack, fixes #16726 !strict.   Also streamlined logic for detecting what part of stack has changed.
Avoid spurious notifications about changes to activeStack, fixes #16726 !strict.   Also streamlined logic for detecting what part of stack has changed.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@30610 560b804f-0ae3-0310-86f3-f6aa0a117693

harbalk/delite,kitsonk/delite,harbalk/delite,Sam-Cummins/delite,Sam-Cummins/delite,kitsonk/delite