Prepare release 3.1.0

Prepare release 3.0.1

Prepare release 3.0.0

prepare 2.9.2-RC4

Gradle: use release flag instead of sourceCompatibility and targetCom…

…patibility.

Fixes FlatBufferBuilder using ByteBuffer instead of Buffer API.

Prepare release 2.9.2-RC2

BoxStore: verify that store is still open before using handle in nati…

…ve calls

Publish: set signing config after publication is known.

Prepare release 2.9.0

Prepare release 0.8.1