Run in previous other window.
Need to (require racket/enter).
Need to (require racket/system racket/path) in case #lang racket/base.
Add call-with-input-file*
Add indents for dict-set, dict-set*, call-with-input-file*
racket-mode-variables takes arg re whether to set or add
Racket inferior mode: Use unless instead of if, delete dead code.

Don't bother supporting the scheme-start-file stuff.
Add for/fold example.