Plugin Autoupdate Filter

This is a plugin to help manage autoupdates in a responsible way. For example:

1. It defaults autoupdates to be on. Keeping plugins up-to-date is one of the the first lines of defense against malicious attacks and technical debt.
2. It provides various mechanisms by which we can turn off autoupdates, such as during specific days/times, for specific plugins, or centralized settings which can turn off all autoupdates.