Revert "Do less deep copies"

This reverts commit cb2f2adb1bd1a88a9fd651fe797592e2cd725941.
Revert "Merge branch 'oplog-localcollection' into devel"

This reverts commit 297b97659b0ca71dd2065242e6d455c7581f4667, reversing
changes made to 204959b5092265455abc2482d17622a8aa3d7b9c.