Tag release 5.6.9 of Protégé.

Tag release 5.6.8 of Protégé.

Tag release 5.6.7 of protege-platform.

Tag release 5.6.6 of protege-platform.

Prepare 5.6.5 release.

Update bundled JRE to 11.0.25+9.

Bump the version number in all POM files. Also update the Windows
launcher, so that the version number displayed in the Windows executable
is updated as well.

Tagging release 5.6.4 of protege.

Merge pull request #1170 from protegeproject/prepare-5.6.3-release

Prepare 5.6.3 release

Tag release protege-parent-5.6.2.

Tag release protege-parent-5.6.1.

Tag release protege-parent-5.6.0.