Improve ASP.NET Ado performance 15-30% by removing CommandBehavior.SingleRow

This isn't necessary because we know that only one row will be returned
and it causes the MySql provider to send two extra commands per query.
This didn't seem to change the PostgreSQL performance.

The ado/mysql test improved about 15% and the ado/mysql/update test
improved about 30%.
Merge branch 'performance_singlerow' of https://github.com/MalcolmEvershed/FrameworkBenchmarks into MalcolmEvershed-performance_singlerow