add index populate events

In my project we are using bulk indexing, and according to [doc](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/indices-update-settings.html#bulk) to increase performant for bulk indexing, we need to have ability call custom actions like: `refresh_interval` and `_optimize?max_num_segments=5`

To achieve that we've added `PRE_INDEX_POPULATE`, `PRE_TYPE_POPULATE`, `POST_TYPE_POPULATE`, `POST_INDEX_POPULATE`, `INDEX_RESET` events.
I'm not happy with this change: if someone programmatically resets the index by injecting the resetter, the event won't fire. As a user I'd expect the event to fire if the index is going to be reset.

Can you move this event into the resetter itself please?