2.1.4

• support for Java > 9 (which previously broke) and compile without deprecation warnings on Java 21.
• update MaryTTS version to 5.3-SNAPSHOT which makes DialogOS runnable again (although, only with one
  single English voice available from maven artifact repositories; the full list remains available
  through the installer)
• removed DialogOS's handling of character encodings. We'll just go with what Java uses, which typically
  is Utf-8.
• updated Gradle (mostly?) across the board to 8.10.2; also updated many dependencies to newer versions.
• better handling for user-defined functions and grammars that do not compile because of syntax errors.
  Now a warning is shown after editing the function/grammar. Note that functions may still fail
  when called at runtime (e.g. because you reference variables that are not accessible) and there is
  no checking for grammars that are created from expressions at runtime.
  However, this will already solve many frequent issues (like missing semicolons.
  (fix for #102, #200, #201)
• left recursion, which leads to unexplainable behaviour in the parser, is now warned about.
• new script function sleep which does what you'd expect (in milliseconds).