Tokutek/mongo — pull request #832 by leifwalsh (2013-12-11 23:22:37+00:00)
Title: Sharding cleanup

- added SpillableVectorIterator to make SpillableVectors easy to use on the from side
- replaced some of the migration code with simpler code based on cursors
- removed cruft from migration like trackerLocks, OldDataCleanup, flushPendingWrites, etc.