TODO:
 * framework
   * change to TrAX
   * add processors
   * add ant tasks
 * features
   * add relative URI support
     - related to adding TrAX
   * add "inherit"
   * document fragments in pipeline
   * better logging
   * add <property> tag
 * documentation
   * complete JavaDoc
   * add (more) samples
 * pipelines
   * add templating system