Drop support for separate console history file

[mvz]

Summary

Aruba console uses its own history file. I don't think it should.

Expected Behavior

History for aruba console should be appended to the general IRB history.

Current Behavior

Aruba console stores its history in ~/.aruba_history.

Possible Solution

Remove the code setting the relevant IRB options, as well as Aruba's configuration option.

Context & Motivation

Having this history separate makes it harder to re-use existing history from general IRB use. Other special-purpose consoles (e.g., rails console) also do not keep a separate history.

[mvz]

We may even drop the whole aruba console feature, and the aruba CLI.