Speed up replay from SQL Server

_From @danbarua on February 13, 2015 10:21_

I'm not sure how relevant this is to V5/6 but this massively speeds up replays on MSSQL:

``` sql
CREATE NONCLUSTERED INDEX [IX_Commits_Ordered] ON [dbo].[Commits]
(
    [CommitSequence] ASC,
    [StreamId] ASC,
    [StreamRevision] ASC
)
```

_Copied from original issue: NEventStore/NEventStore#391_
