MSSQL 2005 datetime2 issue

Currently the store can not be used with MSSQL 2005 because of the CommitStamp column is datetime2.  The datetime2 is supported starting from MSSQL 2008. For MSSQL 2005 datetime has to be used. So I've adjusted the init script so it will use datetime2 if it's supported. In other case it'll fallback to datetime. Persistence tests passed for both MSSQL 2005 and MSSQL 2008. Without the patch MSSQL 2005 fails.