We have this check box that says "Automatically download and install updates in the future." But we only download them automatically. We still ask permission again before installing them.

With this patch, we make good on the description of that box: updates are automatically installed when the app is quit. No user intervention involved whatsoever if they checked that box.

If the user doesn't quit the app for a day after the update is downloaded, we'll show the dialog we've always used for automatically downloaded updates (Install Now / Install on Quit / Skip This Update).
Fixed a no-autorelease-pool leak.
Adding <sparkle:tags> appcast item element, <sparkle:criticalUpdate /> tag

You would use this like:
<item>
    <title>My great update</title>
    ...
    <sparkle:tags>
        <sparkle:criticalUpdate />
    </sparkle:tags>
</item>

The behavior of this tag presently is: rather than waiting for the user to quit the app (or for some large amount of time to pass), the user will be prompted to install the update (with a stronger message) immediately upon its receipt. This behavior could be improved for the manual update case as well.

We can also use this new mechanism to create special behavior for e.g. paid updates.
Prompts the user to update after a week (rather than a day) if he doesn't quit the app.
Updating Sparkle.strings for the new, more strongly worded strings that are displayed for a 'critical update'
Merge branch 'master' into quiet-automatic-update
Merge branch 'master' into quiet-automatic-update
Set up install on quit for critical automatic updates too

Fixes the SUInstallLaterChoice for critical update prompts.
Increment the sudden termination counter if installing on quit
Merge pull request #148 from mattstevens/silent-update-fixes

Silent update fixes
Merge branch 'master' into quiet-automatic-update
Merge branch 'quiet-automatic-update' of github.com:andymatuschak/Sparkle into quiet-automatic-update
Support silent relaunches
Merge branch 'master' into quiet-automatic-update
Allow the delegate to trigger a silent install and relaunch
Merge branch 'master' into quiet-automatic-update
Merge remote-tracking branch 'mattstevens/delegate-auto-update' into quiet-automatic-update
Allow manual checks when an install on quit update is pending
Merge pull request #160 from mattstevens/manual-check-fix

Fix manual update checks when an automatic update is pending
Merge branch 'master' into quiet-automatic-update