INT-3418: Prepare 4.1 VERSION

JIRA: https://jira.spring.io/browse/INT-3418

* Create 4.1 XSD
* Clean up Docs for 4.1
* Prepare WebSocket module
* Add Reactor dependency
* Remove Eclipse and SNV artifacts

Phase #1: prepare

Conflicts:
	gradle.properties

spring-integration-test/.springBeans

@@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<beansProjectDescription>
-	<version>1</version>
-	<pluginVersion><![CDATA[2.3.3.201005102200-CI-R3771-B739]]></pluginVersion>
-	<configSuffixes>
-		<configSuffix><![CDATA[xml]]></configSuffix>
-	</configSuffixes>
-	<enableImports><![CDATA[false]]></enableImports>
-	<configs>
-	</configs>
-	<configSets>
-	</configSets>
-</beansProjectDescription>