Added feature to allow user to have a wildcard for selecting "Any Pipeli...

...ne" or "Any Stage" within a pipeline when subscribing to email notifications.

This pull request is to let a user select to get notifications for any event on all pipelines or all stages on a particular pipeline.

This is useful because it allows users to be able to be notified on events for a pipeline when it changes without having to update their notifications everytime a pipeline changes.