Update Spring version

This change updates the spring dependency to 4.1.1.RELEASE. The porlet
plugin's tests are not compatible with 4.1.1 therefore this change
also forces it to use 4.1.1 until time to be dedicated to updating
the portlet plugin's tests
Rename spring-integration to spring-integration2

This change renames the spring-integration plugin to spring-integration2
and makes way for spring-integration3/4 plugins
Add spring-integration4

This change adds the spring-integration4 plugin. This is just a copy
of the spring-integration2 plugin and does not properly build
Fix compile errors

This commit fixes all compile errors for spring-integration4. Tests do not pass
yet