Maven: Use mirrors

[schnatterer]

Via settings.xml we can setup mirrors for Maven Repos, e.g. central.

<mirrors>
  <mirror>
    <id>${url}</id>
    <name>${url} Central Mirror</name>
    <url>${urll}/nexus/content/groups/public</url>
    <mirrorOf>central</mirrorOf>
  </mirror>
</mirrors>

ces-build-lib could help us doing that.

We already use writing settings.xml for deployment. So we have to create a generic mechanism for settings.xml e.g. using a builder. We also have to assert that the settings.xml is written at least once before mvn / call() is called and that maven uses the settings.xml (-s parameter).