Prototype Microsoft SQL Server database setup

This includes:

* install-client.ps1: a PowerShell script to be run on a Windows Server
  box to download and install SQL Server.
* config/create-sqlserver*.sql: SQL Server T-SQL scripts to create a
  database user and populated database.
* Initial changes to allow sqlserver as a provider for AdoController.cs.

This is somewhat incomplete and needs work:

* How to run the T-SQL scripts if they haven't been pulled down from Git?
* Need wrk or something similar for Windows.
* How to get the python script on the server to run remote commands on the
  client database box?
Merge branch 'master' of https://github.com/MalcolmEvershed/FrameworkBenchmarks into sqlserver
Rename install-client.ps1 to setup-sqlserver.ps1
Improve SQL Server setup scripts

1. Add setup-sqlserver-bootstrap.ps1 that can be run from the web.
2. Run T-SQL scripts at the end of setup-sqlserver.ps1.
3. Make T-SQL scripts delete stuff if necessary.
Finish getting ASP.NET to work with SQL Server

1. Add aspnet-sqlserver-raw and aspnet-sqlserver-entityframework tests.
2. Don't share DbParameter object between two SqlCommand objects because
   SqlCommand objects.
3. Get SQL Server working with the Entity Framework.
4. Tidy up T-SQL.
5. Fix typo in setup-sqlserver-bootstrap.ps1 with config path.
6. Complete SQL Server setup and configuration in setup-sqlserver.ps1.
Update README.md for SQL Server instructions
Make SQL Server inserted strings Unicode

Since the column is nvarchar, the string constants that are inserted
should be prefixed with N like N'foo' instead of 'foo'. This fixes the
Japanese string.
Add SQL Server to README.md

SQL Server is now supported via the SqlClient provider.
Merge pull request #336 from MalcolmEvershed/sqlserver

Get SQL Server working with ASP.NET tests on Windows