Remove duplication in specs
Less design-patterny name for visit messages
Remove useless instance var
Remove duplication in eval_visitor
Less design-patterny name for evaluator
Remove 'visit_' prefix from self-description messages
Simpler variable names in evaluator
Bring Java into line with Ruby visitor interface
Bring Javscript into line with Ruby visitor interface
Restore type names in Javascript for better debugging
Merge branch 'master' into refactoring_suggestions