Enhance the project generated by the wizard when 'Use Java Services' is checked

[echebbi]

Motivation

Checking Use Java Services in the New ALE Project wizard means that the user will call Java services from ALE. That usually requires:

• to generate Java code from the Ecore model,
• to add EMF to the project's classpath.

However the generated project is not a plug-in project and doesn't allow to generate Java code from an Ecore model.

Proposed Solution

When asked for Java services, the wizard also:

• adds the Plug-in nature to the project,
• creates an EMF generator model (.genmodel) in the model/ folder

Proposed Implementation

Complete AleWorkspaceProject::addJavaNature as needed.