Javadocs are generated in the following steps:
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1. pom file is generated
   * maven invoker plugin runs javadocs-builder/src/it/generate-javadocs-pom-file
   * generated pom file is copied to javadocs-builder/src/it/generate-javadocs-file
2. javadocs jar file is generated
   * maven invoker plugin runs javadocs-builder/src/it/generate-javadocs-file
3. generated javadocs jar file is attached to deployed artifacts
   * see wildfly-aggregate-javadocs/pom.xml
