Autocomplete CE changes

the-plan.txt

* Import CE
* Change the relevant extends
* Manually set autocomplete="off"
* this.inputField --> super
* Remove appended markup
* Replace the popupset
* crop() attribute
* focused() attribute
* _setValueInternal method (everything involving inputField)
* selectTextRange method
* textValue() attribute
* Remove value() attribute
* this.mController.input = this.getCustomInterfaceCallback(Ci.nsIAutoCompleteInput);
* Remove:
```
if (aEvent.target.localName != "textbox")
      return true; // Let child buttons of autocomplete take input
      ```
*
```
      if (!this._popupset) {
        this._popupset = document.createXULElement("popupset");
        document.documentElement.appendChild(this._popupset);
      }

      this._popupset.appendChild(popup);
      ```
* Remove onBeforeValueSet
* Replace this with this.nsIAutoCompleteInput where needed