Allow setting defaults for new applications

Because I value something akin to serenity, I would like _most_ notification types disabled by default. I would like to be able to create a "default set" in the Notifications switchboard plug which all newly installed applications would inherit. I don't want sounds, and I never use the Notification Center. Bubbles are okay for a test run, but I will probably disable them manually. tl;dr Silence is golden, please don't make me click so much. Many thanks!

_For what it's worth, I had the intuitive impression that "Other" _might_ double with this kind of use, but it apparently does not._