Add OSGi metadata to jnr-ffi.

[rgrunber]

Use maven-bundle-plugin to generate OSGi metadata and include the
manifest using maven-jar-plugin.

This change only adds additional entries to the MANIFEST.MF shipped in the final jar artifact. The attributes would not affect current consumers of this artifact.

[tolbertam]

Has anyone gotten this to work? I'm having problems because jnr-ffi imports com.kenai.jffi (coming from the jffi library) which lacks bundle metadata:

ERROR: Bundle com.datastax.driver.core [13] Error starting reference:file:../../driver-core/target/cassandra-driver-core-2.1.10-SNAPSHOT-shaded.jar (org.osgi.framework.BundleException: Unresolved constraint in bundle com.datastax.driver.core [13]: Unable to resolve 13.0: missing requirement [13.0] osgi.wiring.package; (&(osgi.wiring.package=jnr.ffi)(version>=2.0.0)(!(version>=3.0.0))) [caused by: Unable to resolve 19.0: missing requirement [19.0] osgi.wiring.package; (osgi.wiring.package=com.kenai.jffi)])
org.osgi.framework.BundleException: Unresolved constraint in bundle com.datastax.driver.core [13]: Unable to resolve 13.0: missing requirement [13.0] osgi.wiring.package; (&(osgi.wiring.package=jnr.ffi)(version>=2.0.0)(!(version>=3.0.0))) [caused by: Unable to resolve 19.0: missing requirement [19.0] osgi.wiring.package; (osgi.wiring.package=com.kenai.jffi)]
    at org.apache.felix.framework.Felix.resolveBundleRevision(Felix.java:4097)
    at org.apache.felix.framework.Felix.startBundle(Felix.java:2114)
    at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1368)
    at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308)
    at java.lang.Thread.run(Thread.java:745)

[tolbertam]

I see, both redhat and debian provide packages for jffi-native that are proper OSGI bundles so granted you use the jars provided by those packages it should work.

[tolbertam]

I created a pull request (jnr/jffi#29) for providing OSGi metadata for jffi/jffi-native as part of the build process. Confirmed that I can use jnr-ffi in OSGi 👍