SERVER-16108: Remove extra Timer and std::string in AutoGetCollectionForRead
SERVER-16046: do oplog cleanup in a different txn so it can fail
remove scope of locking when putting sessions back into pool
SERVER-16109: remove excessive log syncing in WT size storer
SERVER-16013 Wrap WiredTiger callbacks called from C in try-catch blocks.
Merge remote-tracking branch 'upstream/master'