Add OSGI headers to manifest

[shakanen]

Adding OSGI-headers to MANIFEST.MF helps to use this library in OSGI-container. The additional headers have no impact to other environments which don't read them. One easy way to achieve this is to use either https://github.com/bndtools/bnd/tree/master/maven/bnd-maven-plugin or https://felix.apache.org/documentation/subprojects/apache-felix-maven-bundle-plugin-bnd.html