Clever/oplog-replay — pull request #27 by kvigen (2014-11-14 20:23:43+00:00)
Title: Add alwaysUpsert flag

Adding this flag based on the documentation here:
https://github.com/mongodb/docs/commit/238d6755a74c3c978cc272d318283f726379a43c.

For backwards compatibility setting the default to alwaysUpsert = false.