First seemingly working attack making maximal_flushable_txn_set implemented.
Fixed some trivial bug with began_waiting_for_flush_ check in maximal_flushable_txn_set (sigh).
Added comments in maximal_flushable_txn_set.
Removed the unused function exists_flushable_txn_set.
Made remove_txn_set_from_graph not fallaciously try to find a newly flushable txn set.
Replaced extraneous std::set use with std::vector for our precious outer loop performance.
Added if (!poisoned) around the marked_not subseqer case in the cache.
Merge branch 'sam_multiple_index_writes' into sam_multiple_iii_better
Adjusted comment.
Revert "Adjusted comment."

This reverts commit 459ed5f8d4abd4dda6b14e3b4882f8b383106bf1.
Revert "Merge branch 'sam_multiple_index_writes' into sam_multiple_iii_better"

This reverts commit 7378bee3ed6479dd3e30a2565d8be5cd220ab02b, reversing
changes made to 3868a1b2eb4771ed18c1407f023d8b522735fdb2.
Revert "Merge branch 'next' into sam_multiple_index_writes"

This reverts commit 3868a1b2eb4771ed18c1407f023d8b522735fdb2, reversing
changes made to 535993098ed9852268145fd0bf06be49cef1f178.
Revert "Revert "Merge branch 'next' into sam_multiple_index_writes""

This reverts commit cda0e411e51c564513bd070fabaafa57f8bf109f.
Revert "Revert "Merge branch 'sam_multiple_index_writes' into sam_multiple_iii_better""

This reverts commit 98ceb787862e62feb11f7aee3aa1e1afd842bcb4.
Revert "Revert "Adjusted comment.""

This reverts commit 91370aac2cba6a953dede6755e33c0c683757571.