ns-reloader doesn't always reload the wrapped process when namespace labels change

[ianlewis]

When using a namespace selector, if a namespace's labels change resulting in the namespace selector no longer matching the namespace, a watch event is not triggered. This can be problematic because ns-reloader will not trigger a reload.

[ianlewis]

This seems to be an issue for negative label selectors like !labelname. I'm not sure about other label selectors.