rewind() {
    // Create snap shot if not yet recorded
    if (this.$editable.html() !== this.stack[this.stackOffset].contents) {
      this.recordUndo();
    }

    // Return to the first available snapshot.
    this.stackOffset = 0;

    // Apply that snapshot.
    this.applySnapshot(this.stack[this.stackOffset]);
  }
@method rewind
Rewinds the history stack back to the first snapshot taken.
Leaves the stack intact, so that "Redo" can still be used.