Added maven pom.xml files.
Update generated files
Update gitignore
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.
Update generated build file.
Merge branch 'master' into mvn-build

Conflicts:
	org.metaborg.meta.lang.nabl/META-INF/MANIFEST.MF
Fix missing comma
Add project metadata to POM files, required for publishing to the Maven central repository.
Update generated pretty printer file.
Merge commit '37c26efb368344d0278694ce2a37c84088b11937' into coq-semantics