Explain `3<Esc>` as [aborted command]
Explain `"a<Esc>` as [aborted command]
Explain `2"x3<Esc>` as [aborted command]
Make cut_command abortable
Refactor test for explaining aborted commands
Explain `r<Esc>` as [aborted command]
Explain aborted mark commands
Add a `rake visualize` task to generate .dot