Feature roadmap/Activity updater improvements

Feature subcategory		Is part of::Category:Activity-related work
Requesters		{{#arraymap:Scott|,|x|Requested by::x}}
Requirements
Specification		* Real COW for pristine versions, allowing... <trac>3581</trac> ...binary-diff updates over http (avoiding rsync in many cases) <trac>4259</trac>, etc Integration of core OS updates with software update control panel: <trac>7618</trac> (See also GUI OS Updater feature) Integration of software updates with notification system Incremental updates of activity bundles (only changed files) Send back statistical data when checking for updates (batmon, etc) <trac>4594</trac>, <trac>6447</trac>
Owners		{{#arraymap:Scott|,|x|Contact person::User:x}}
Priority		Priority::2
Helps deployability?		Helps deployability::no
Target for 9.1?		Target for 9.1::no