Fixes GH-166 (https://github.com/spring-cloud/spring-cloud-stream/issues/166)
Since `onInit()` in the `MessageChannelBinderSupport` was called before the `evaluationContext` population,
the `RedisMessageChannelBinder#errorAdapter` caused `NPE` for its `evaluationContext`.
* Change the initialization order
* Use `ExpressionUtils` to populate `evaluationContext` - creates `StandardEvaluationContext` if there is no one in the `applicationContext`
* Add more initializations for the `RedisMessageChannelBinder#errorAdapter`
* Remove explicit `evaluationContext` population from the `AbstractTestBinder` to rely on the fix for this ticket
* Some other simple polishing
Address PR comments
2e7f9cc729