`log.empty()` is the same as `log.reset()`, except thati `empty()` also returns the current array with messages
instead of:
```
// do work
expect(log).toEqual(['bar']);
log.reset();
```
do:
```
// do work
expect(log.empty()).toEqual(['bar']);
```
jQuery's elem.html('') is way slower than elem.empty(). As clearing
element contents happens quite often in certain scenarios, switching
to using .empty() provides a significant performance boost when using
Angular with jQuery.
Closes#4457
Issue: multi-elements ng-repeat (ng-repeat-start, ng-repeat-end) can contain elements with a trancluding directive. This directive changes content of the row (template) and ng-repeat does not work correctly (when removing/moving rows), because ng-repeat works with the original template (elements).
This changes ng-repeat behavior to traverse the DOM to find current elements everytime we are moving/removing rows (if the template has multiple elements).
Closes#3104
