Event Propagation Updates:

[amiller-gh]

• As events are propagated up, named change events are fired for each data obj they have passed through on that layer
• Added path utils helper
• Computed properties set .toJSON'd data instead of original data elepemt to prevent shared objects
• Collections how have changedAttributes() and hasChanged() methods
• Enable nested collections
• Performance enhancements for ComputedProperty and Render evaluation
• Bump htmlbars