- Fix registrion of preconstructed query provider (refer to neste class);
- preconstructed query provider nested class is static so that ServiceLoader can instantiate it;
- Fix error message in QueryProviderRegistry (supply queryID as parameter to String.format).
- Add error page that shows exception message and stacktrace.
- Check for null values.
- Config file is a stream, relative to the servlets context path.
- ErrorPage for jang.lang.Error