gchp/iota — pull request #59 by pythonesque (2014-12-23 04:00:28+00:00)
Title: Adding undo and redo.

This involves adding transactional semantics to all commands that modify
data. This is explicitly *not* optimized right now, but is instead as
simple as possible. If it proves damaging in the immediate term, we can
easily bound the size of the undo/redo stack.

This builds off the commit that fixes deletion at end of line.