Move Spring Web Services to 3.0.0.BUILD-SNAPSHOT
Key updates include:
* Rebase against Java 8
* Spring 5
* Smack 4.2
* Removal of wss4j 1.x support
* Gradle 4.0
* Plugins
This commit migrates from a Maven-based build system to a Gradle-based
one. Changes include:
- Removed archetype & parent
- Renamed core, support, test, security and xml directories to
spring-ws-core, spring-ws-test, spring-ws-security, spring-xml
respectively.
- Moved samples to separate project
(https://github.com/spring-projects/spring-ws-samples)