Adding boundng box and center point to model objects.
Merge branch 'master' of github.com:calpath/model-objects
Merge pull request #18 from mnjuhn/master

Adding bounding box and center to network
Sensor SensorSet model_objects partial
Classes assoicated with the Sensor and SensorSet
Re-factored model objects classes to different package as well as changed some of the getters/setters to use the super class
Network Schema changes, adding geometry object to get WKT.
Merge pull request #19 from mnjuhn/master

Network Schema changes, adding geometry object to get WKT.
SensorSet and Sensor partially complete along with partials of classes referenced by Sensor and SensorSet
Merge pull request #20 from sean-morris/master

Sensor and SensorSet
re-factored SensorFactory to return a generic Sensor in createSensor
Merge pull request #21 from sean-morris/master

ScenarioFactory.createSensor refactored
5 of the measurement objects and the object factory - initial commit