OpenKit Java Reference Implementation
https://github.com/Dynatrace/openkit-java/blob/release/1.4/CHANGELOG.md
https://github.com/Dynatrace/openkit-java/blob/release/1.3/CHANGELOG.md
https://github.com/Dynatrace/openkit-java/blob/release/1.2/CHANGELOG.md
https://github.com/Dynatrace/openkit-java/blob/release/1.1/CHANGELOG.md
Fix wrong value for Content-Length HTTP header that was added when sending beacon data.