Notifiers are data-less callbacks and a notifier list is a list of registered
notifiers that all are interested in a particular event.
We'll use this in a few patches to implement mouse change notification.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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v1 -> v2
- Do not do memory allocations by placing list nodes in notifier
Anthony Liguori