Calculate indent level.
when reach eof, output outdent blocks
fix lexer for eof
Add class method test case
update parser test for CreateLexer
Fix grammar for line breaks
class method/property grammars
Add '@' token type for refering class member
rebuild parser
Add class member ast node.
Lexer new keywords: new, clone
Add CreateUnaryExpr method
Rename ClassStatement to Class
Shorter name: AssignStatement => Assignment
AST: Set class body