#31 Allow editing of command line

[Jonathan Hepburn]

While the command line is being displayed, it would be
an advantage to allow it to be edited. This would
remove the need to dive into Advanced preferences for
every minor change while debugging, and would allow
fine-tuning for those lazy enough to sue fgrun, but
knowledgeable enought to not need it for everything.

[BATTLEMASTER]

I second this.