Add system def file
Add vertigo package def
Fix :delimited parser expansion
Add parser expansions from the prep compiler
Add parser utilities
Declare package, add utility rule
Add vertigo-test package
Add integer and decimal AST node structs
Add decimal rule unit tests
Don't convert int/frac parts of a rational
Add datetime AST node structs
Add numeric literal unit tests
Return value from numeric literal
Add datetime literal unit tests
Use integer rule in date literal
Be more robust about parsing date literals
Add string AST struct
Add string literal unit tests
Fix bugs in string escape parsing
Add justify, translate, and reserved params for strings