Add compatibility with Java 13

[Don-vip]

Followup of #16498

First ​​EA builds of Java 13 are available.

See #17827 for Java 14 compatibility.

[Don-vip]

In 14784/josm:

see #17516 - upgrade to error_prone 2.3.3-SNAPSHOT + patch for Java 13 compatibility

See ​https://github.com/google/error-prone/issues/1106#issuecomment-460800327

[Don-vip]

In 14939/josm:

see #17268, see #17516 - add missing semicolons (issue reported by javadoc 13)

[Don-vip]

Java 13 builds are crashing for two months now, even if I reported the bug: ​javabug:8219902

[Don-vip]

In 15128/josm:

see #16047, see #16498, see #17516, fix #17723

• add java.scripting module when loading JOSM with Java 11+
• detect java 12/13 on Linux

[Don-vip]

New compilation warning:

    [javac] /var/lib/jenkins/jobs/Java-EarlyAccess-Integration/workspace/jdk/JDK13/src/org/openstreetmap/josm/io/audio/AudioPlayer.java:297: warning: 'yield' may become a restricted identifier in a future release
    [javac]             yield();

[Don-vip]

In 15181/josm:

see #17516 - use qualified access to Thread.yield() as it is a restricted identifier in Java 13, see ​https://bugs.openjdk.java.net/browse/JDK-8223305

[Don-vip]

​javabug:8223552 impacts us and raises several javadoc warnings.
It is closed as won't fix with following workaround:

Use -Xdoclint:-html to disable HTML checking. The option is available in JDK 8 and subsequent releases.

[Don-vip]

In 15243/josm:

see #17516 - Disable HTML checking until we switch to Java13+, see ​https://bugs.openjdk.java.net/browse/JDK-8223552

[Don-vip]

Java 13 has been released: ​https://www.oracle.com/technetwork/java/javase/13all-relnotes-5461743.html

[Don-vip]

In 15379/josm:

see #17516 - update linux start script

[Don-vip]

In 15963/josm:

see #17516 - update to error-prone 2.3.5-SNAPSHOT plus following patches for Java 13 compatibility (​https://github.com/don-vip/error-prone/commits/jdk13):

• ​https://github.com/google/error-prone/pull/1107
• ​https://github.com/google/error-prone/pull/1110
• ​https://github.com/google/error-prone/pull/1111
• ​https://github.com/google/error-prone/pull/1398
• ​https://github.com/google/error-prone/pull/1439

[Don-vip]

In 15974/josm:

see #17516 - update error-prone dependency

[Don-vip]

In 16156/josm:

see #17516 - see #17827 - see #18755 - Enable Jacoco coverage on Java 13/14/15

upgraded jacocoant to jacoco-0.8.6-20200313.013328-40 snapshot

[simon04]

In 17853/josm:

see #17516 - Update to ProGuard 7.1.0-beta3 for Java 13+ support