[feature request] support undo state.

[trusktr]

For example, if I have

if (tru|e) {}

where the cursor is at |, then I can type ciw"hello<c-c> which will change it to

if ("hello") {}

Now, suppose I search for all instances of true in the code, then press n. to go to the next result and apply the same change. It won't work, but it'd be awesome if it did.