Increase the version number of Xtext (issue #116).
Revert "Increase the version number of Xtext (issue #116)."

This reverts commit b98e4631ad2a7ae0a6632293911e0c1d70d6b1d2.
Apply the requirements in the POM for Maven Central (issue #128).
Update FAQ.

Add the question: where to ask something?
Reinject the SARL Maven repository.