Miguel Fonseca issues

Results 2 issues of


                                            Miguel Fonseca

[display:none on referenced elements causes java.lang.IllegalArgumentException](https://issues.apache.org/jira/browse/BATIK-1370)

- Code and tests migration to ical4j 4.0.2 - Java 8 to Java 11 (required on ical4j 4.0.x) - Some dependencies updates