Add support for sqlserver in sql backend

This addresses #28 by adding the MS SQL Server backend as a
fully-supported backend.
Fix bug where connection properties are ignored for all databases

The Java Properties constructor optionally takes another Properties
object. However, this merely creates an **empty** properties object.
That is, the keys are there, but the values are not. The Properties
object provides no good facility for creating a new "clone" of an
existing object. While not ideal, we can get around this because
Properties (oddly) subclasses HashMap. So a "putAll" does the trick.
Cleanup unused imports and GivenWhenThen mixin
Cleanup unused imports and fix formatting
Backends and Tests to support SQLServer

This commit closes #28
Bump DataExpress Version number ahead of release
Merge pull request #29 from cbmi/sqlserver_support

Add support for MS SQLServer