Use Lutron keypad button label as the display name for the button
device. That I wasn't before was a holdover from before buttons
were SgDevices of their own.
Show whole-house area in list of areas.
Record DSC partition status changes.

This is a bit hacky and not fully tested; it's not obvious from the
docs that I can precisely define and understand the state of a partition
and query for it at any time.