3 note editing bugs

[dreeves4321]

• The user can produce repeating # shortcuts and placeholders that appear to be zombies. Place the cursor between two shortcuts or placeholders (or a mix). Hit enter. The second is copied in a funny way.

• after deleting a shortcut or placeholder, undo (command-z) replaces the styled text but not the underlying context or meaning.

• Begin typing a shortcut or placeholder. Before hitting enter, move the cursor to the beginning of the phrase and hit enter. Something unexpected is inserted.