[Sprint 38] XD-2216 Update Spring Framework, Integration, AMQP

JIRA: https://jira.spring.io/browse/XD-2216

- Update Spring Framework to 4.1.1
- Update Spring Integration to 4.1.0.BUILD-SNAPSHOT
   -- Required due to a number of bugs in 4.1.0.RC1; if Spring Framework slips beyond XD M1, we will create SI RC2
- Update Spring AMQP to 1.4.0.RC1
- Fix tests for changes in AMQP Header Mapper
- Switch to Jackson2
- Rename test `completion` package to `completionnoscan` (see JIRA comments).
- Fix deprecations

__NOTE: Interim PR, awaiting Spring Framework 4.1.2 - if it is delayed further, we will create Spring Integration 4.1.0.RC2__
__Please merge ASAP so we get as much SI 4.1 exposure as possible before its release__