#1205 Implement step into in ASTDebugger

Originally at 2015-11-20T16:14:55Z by Javier Pimas high level implementation idea would be: ASTDebugger>>#stepInto delegates to ASTInterpreter>>#stepInto. ASTInterpreter>>#stepInto does s.i. only if it is a send, else does just step over. It does something similar to the first part of #visitSendNode:, but instead of sending sendMessage:to:superSend: should do something a bit different activateMessage:to:superSend:. To see how activating a method in low-level, maybe seeing the implementation of perform give some clue <bountysource-plugin> --- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/28461781-implement-step-into-in-astdebugger?utm_campaign=plugin&utm_content=tracker%2F79201&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F79201&utm_medium=issues&utm_source=github). </bountysource-plugin>