Proof of Concept for module contributions based off Boot

Develop out a Proof of concept for review that allows users to easily create a new module to Spring XD. Key features to be enabled:

1. Allow existing modules to be included as a classpath dependency
2. Consolidate shared libraries in existing modules (e.g. a shared lib for all gemfire modules)
3. User develops a module as a normal Java project
4. User's project can then be added to a runtime container in the same way (as a dependency)

Nice to have:

1. at development time container can run continuously and pick up changes from user's module project.
2. Java config for a module.
3. command line functionality to create project scaffolding.