Motivation:
8fdf373557 introduced the @Skip annotation which allows to optimize the way we invoke ChannelHandlers when traversing the pipeline. Now that we moved all the "default" code to the ChannelHandler interface we can make the annotation package-private to guard the user to make any mistakes which will lead to hard to debug issues.
Modifications:
Move ChannelHandler.Skip to ChannelHandlerMask.Skip and make it package-private
Result:
Guard users from introduce hard to debug issues.