Added `Scene.drillPick` for picking of multiple primitives
handle multiple ways of hiding primitives
changed test to check if setShow function is defined
fixed doc comment
Merge branch 'master' of https://github.com/gbeatty/cesium into multiPicking

Conflicts:
	CHANGES.md
	Source/Scene/Scene.js
Begin EcmaScript 5 refactoring for DynamicScene

1. Refactor DynamicBillboard to use ES5 properties and raise property changed events.
2. Refactor DynamicObjectCollection to improve the API and event notification.

CompositeDynamicObjectCollection is busted until it is also refactored.
Merge branch 'dynamicScene-properties' into dynamicScene-es5-properties
Merge branch 'dynamicScene-properties' into dynamicScene-es5-properties
Start refactoring CompositeDynamicObjectCollection

This also involves refactoring DynamicObject to generate proeprty notifications.
Merge branch 'dynamicScene-properties' into dynamicScene-es5-properties
Ongoing refactoring.
Ongoing CompositeDynamicObjectCollection refactor.
Merge branch 'master' into dynamicScene-es5-properties
Merge remote-tracking branch 'origin/issue1094' into dynamicScene-es5-properties
Merge branch 'master' into dynamicScene-es5-properties
Merge branch 'master' into dynamicScene-es5-properties
Removed Cartesian2.prototype.add
Removed prototype.add for Cartesian3/4
Fixed specs to work with Cartesian2.add
Merge branch 'master' into dynamicScene-es5-properties