Initial support for MS SQL Server. 
TODO: Manage the lifecycle of dropping and adding tables in the schema.
For now, the database, nanotrader/nanotrader user and *sqlserver* files
must be manually managed. Skip the load-schema phase by passing in 'ant
-Dis.load-schema.installed=true' and the rest should work. Reference the
springtrader/build.properties for other properties to pass into the
command line like springtrader.dbhost, springtrader.dbport, etc.