When we install a tool, also create a sub-table of user.rootUpdates.servers, with the date pulled from the tool's info table, if it's present. This way next time it updates, it won't have to update parts it already has.

AC noted that the first time he updated a freshly installed river2.root it downloaded 160 parts. While this doesn't do any harm, it seems fairly inelegant.

Part: opmlEditor.addToolToUpdates