add sql server driver for linux to drivers tested when setting driver_needs_utf8

[dmknoll06]

Microsoft has a SQL Server driver for linux (http://www.microsoft.com/en-us/download/details.aspx?id=28160)

Sending utf-8 to this driver will corrupt data. It needs parameters to be sent to pyodbc in unicode strings, like other SQL server drivers.

I'm not really advocating accepting this patch, it just demonstrates the smallest possible code change that fixes the issue. I'm not sure if it makes sense to do something like this, to make the list of microsoft drivers configurable, or to directly make the driver_needs_utf8 value configurable.

The full driver name includes a version string, hence the current awkward way the condition is written. if you want to stick with fixing it here, probably looks nicer as something like:

if any(driver in self.drv_name for driver in ('SQLSRV32.DLL', 'SQLNCLI.DLL', 'SQLNCLI10.DLL', 'LIBSQLNCLI'))