New UUID generation
New UUID generation

addresses #203

# This is a breaking change for all configured homekit databases, as it
will remove room/area assignments and other things configured in iOS
apps
... unless your accessory type was called `Object` before

Changes:
- Without any changes to the configuration file all accessories UUIDs
will be generated by  `uuid.generate(accessoryType + ":"` instead of the
constructor name which turned out to be unreliable in that context. So
about all UUIDs will change.
- new parameter uuid_base can be used for accessories in config.json to
use a different base for UUID generation than the displayName, which
might not be unique
- platforms can add the same property to their accessories before
returned, just as they have a name property right now.

nfarina/homebridge,dvinc/homebridge,felixekman/homebridge,thkl/homebridge,chrisi21/homebridge,snowdd1/homebridge,dotsam/homebridge,inonprince/homebridge,patricks/homebridge,EddyK69/homebridge,nfarina/homebridge-legacy-plugins,SphtKr/homebridge,hplato/homebridge,travisdoyle/homebridge,nfarina/homebridge