Add OSGi manifest headers
Add OSGi manifest headers

This change moves to using the biz.aQute.bnd Gradle plugin to
produce OSGi-compatible manifests in jar files. Currently, only the
org.agrona.core module has been updated to provide OSGi metadata
because the Agrona agent should never need to be visible inside an
OSGi container. Care has been taken to preserve the existing defined
manifest fields (Automatic-Module-Name, Implementation-Title, etc).

real-logic/Agrona