MongoId strings not returning.

I have a Ground subscription that contains MongoIDs in string form as the main id. When I do a find, it lists it out, however when I do a find or findOne on the id, it doesn't return anything.

Here's an example of one that fails:

`DRAFTS.findOne({_id:"58d887874e0ca825443236cf"})`

I suspect that it has something to do with mongo-id package and this function: `MongoID._looksLikeObjectID(id)`

I haven't been able track it down at all though.

Reproduce the failing findOne call with the string-form _id, then inspect MongoID._looksLikeObjectID and the mongo-id package behavior it relies on. Done means find and findOne return the record for the supplied string ID, while preserving the existing behavior for other IDs.

Written by the indexing model from the issue text.