Added maven pom.xml files.
Update generated files
Update gitignore
Adapt to new language build.
Use old build because SDF3 has a custom build.
Adapt to new language build.
Fixes for two-stage build and cleanup.
Made strj and the generator Java projects. Remove dependence on strategoxt.jar for everything.
Remove versions from external dependencies and plugins, are now managed by the parent pom.
Update generated build file.
Merge branch 'master' into mvn-build