We needed to be able to set the application name in a mssql connection
string, but php doesn't current toy support it.
This can be very helpful while debugging/profiling php-mssql from the SQL
server side of things.
Without this patch all mssql connections have a hard coded application name
of 'PHP 5'.
Please let me know if you have any problems applying the patch or comments
on how we can make it better/get it added to the main codebase.