Add a path to hold downloaded updates.
Download to the updates folder.
Remove public blob stuff from Sign tool
Don't make a path for this.

This will make downloaded updates more visible. We don't want this
before we have a chance to verify them.
Add an update installer tool.
Add the InstallUpdate utility to the solution.
Add information for the signature url.
Add configuration paths for signatures.
Correct the signature urls.
Don't show the update download path in the log.