2022-10-04  Geert Bevin  (gbevin[remove] at uwyn dot com)

  * Re-implemented template engine using ANTLR for faster parsing.
  * Changed template engine tags formats to align better with modern
    conventions.
  * Proof of concept re-design of site and element infrastructure
  * Integrated embedded Jetty server for standalone use.
  * Set up Gradle build system.