Reduce the chance of undesired concatenated document IDs

There seems to be a chance that multiple transition_post_status
calls could occur on one page load. I'm hoping that it's this
causing the super long repeating document IDs being stored in ES
Use save_post rather than transition_post_status

There is a good chance using transition_post_status is causing
confusion by firing at multiple times
When a post is trashed, use before_delete_post to delete from ES

By the time delete_post fires, we don't have a post meta ID.
Rename method to remove_post_from_index rather than delete

Allows us to reuse this code when something is happening to put
content in a non 'publish' state
Merge pull request #2 from washingtonstateuniversity/bug/concat

[PR] Resolve issues with ID concatenation and disappearing indexes