set the library version to 2.6.0 for the release.

documented 2.5.0 version changes in CHANGELOG.md

publishing 2.4.0 release changes

added release notes for versions 2.2.0 and 2.3.0 to CHANGELOG.md

set version to 2.1.0 for the release

set the version to 2.0.0 for the release.

Updated the required Java version. it's "6+", not "6".

Saying "6" can be misleading.

set version to 1.24 for the release.

use unique IDs in ParentProjectTest so that it does not fail

- otherwise it can fail when the previous test did not delete the temporary project

set version to 1.22 for the release