Add __repr__ method to SimpleStatement and PreparedStatement. This should help
with debugging.
Throw InvalidParameterTypeError  exception if user trys to bind
PreparedStatement with an argument of an invalid type.
Modify InvalidParamaterTypeError to inherit from TypeError.
Also include consistency level in the __repr__.
Merge pull request #25 from Kami/throw_better_exception_when_binding_preparedstatement_with_invalid_type

Throw a better exception which user binds PreparedStatement with an argument of an invalid type