Fix some NullPointerException issues in debug dump
Update UACA listeners, add some implementation drafts
Add enum support for string constants
Update references to enum supports
Add first core AST utilities API draft
Fix some bugs in the core AST API draft
Implement some stuff and add notes to AstNodes
Move AST difference related classes into separate package
Extend AstDifference from ForwardingSet
Fix minor issue in core AST implementation
Add more TODOs to core AST API
Add enum for resource member flag constants
Improve resource delta debug output
Add more utilities for Eclipse resources