Added Multiple Structure and Device support

Added models Structure and Device.
Allows for multiples of each and setters can be called on nest/structure and will affect all the children
Do to the new models I added in a flag for initializing structures.

Refactored a bit of the initialization of Nest in order to help this refreshing.

Looking to go get a smoke alarm to so that we can subclass devices into thermostat and smoke alarm.  Might consider changing the namespace at that time off of NestThermostat to Nest and changing Nest to Account