allowing multiple nodes to represent the same directory in the model
changing model so defaultBladeset represents the app directory
allowing optional default aspects and using a subclass for DefaultAspect and DefaultBladeset
refactoring to remove some duplication
adding some javadoc for the changed bladeset/aspect methods
adding some simplified app structure tests for dependency insight commands
uncommenting exception when a registered node already exists
adding default aspect/bladeset tests for build/import/export app commands
adding default aspect tests for content plugins
adding a default aspect test for when an app is being served
adding test to make sure test bundles can be run for default aspect
Merge branch 'develop' into simplified-directory-structure

Conflicts:
	brjs-core/src/test/java/org/bladerunnerjs/spec/command/ImportAppCommandTest.java
Merge branch 'develop' into simplified-directory-structure

Conflicts:
	brjs-core/src/test/java/org/bladerunnerjs/model/engine/MockRootNode.java
moving getTypeName on to Node interface
changing instances of getClass().getSimpleName() to use the new getTypeName method
moving implicit/explicit default logic from App into a static AppUtility
Merge pull request #893 from BladeRunnerJS/simplified-directory-structure

Simplified directory structure