support applyOps in the oplog

Mongo has a command called [applyOps](http://docs.mongodb.org/manual/reference/command/applyOps/) that lets you apply an array of oplog entries to a mongod instance. When we used this, we noticed that MoSQL wasn't replicating these operations properly. We looked into it and it turns out that [oplog entries from applyOps aren't formatted like normal oplog entries](https://groups.google.com/forum/#!topic/mongodb-user/dTf5VEJJWvY).

This change allows MoSQL to handle oplog entries from applyOps easily by calling `handle_op` for each operation in the array.