Allowing for own connection params with backwards compatibility

[owencraig]

When used as default in an app (such as an express web app), you're only able to have one connection at a time. We've got a use case which would benefit from the ease of calling just the query interface but to have multiple connections possible.

This allows for a non-breaking usage with

query.connectionParameters = 'foo';
query.query('select * from bar');

But also extends the interface with

query.ownConnection('foo','select * from bar')