Hard coding the default file structure.
Remove announce method, which Lucid never used.
Feature and Background visitor calls.
Tags visitor calls.
Comments visitor calls.
Feature Element visitor calls.
Examples visitor calls.
Features visitor calls.
TestDef JSON can generate again.
All step and outline visitor calls.
All calls from AST to formatters are now implicitly handled.
Better handling of keywords.
Formatters now rely on a step result construct.
Merge branch 'refactor_visitor' into develop