add support for BLOB, etc.?

[dmalan]

I'm not sure how to pass them at the moment, since we're reducing the whole statement to a str ourselves. And a query like

db.execute("SELECT * FROM Employee WHERE FirstName = ?", b'\x00')

currently errs with

ValueError: the query contains a null character

at this line of ours:

result = self.engine.execute(statement)

@kzidane, know how/if we can represent binary data in strings in a cross-DBMS way? Or do we need to revert to binding parameters for those?