Fix several issues with behaviors

[brianpeiris]

• Add type properties to all behaviors so that they can be retrieved with getBehaviorByType
• Account for parent scale and rotation in the Drag behavior, making it more robust to varied use cases
• Properly dispose event handlers in Drag and HoverColor behaviors
• Fix removeAllBehaviors so that actually removes behaviors
• Add unit tests for behavior system
• Fix default config in HoverScale behavior
• Add configuration options to the Bob behavior
• Add a functional test that demonstrates several behaviors
• Add npm scripts for building JS and docs
• Miscellaneous cleanup
• Whitespace cleanup