* Make filter operator examples easily editable
* Add 'Reset' button to filter operator examples
* Only display the reset button when filter has changed
* Introduce '.doc-example input' class rather than re-use tc-advanced-search to make input wider
* Grab focus for the filter text box
* Fix firefox ctrl-z/undo issue by replacing list widget with filter transclusion
* Replace spaced indent with tabs to make it consistent with the other code