Check plugin Lucene version

Check that a plugin is Lucene compatible with the current running node using `lucene` property in `es-plugin.properties` file.

* If plugin does not provide `lucene` property, we consider that the plugin is compatible.
* If plugin provides `lucene` property, we try to load related Enum org.apache.lucene.util.Version. If this fails, it means that the node is too "old" comparing to the Lucene version the plugin was built for.
* We compare then two first digits of current node lucene version against two first digits of plugin Lucene version. If not equal, it means that the plugin is too "old" for the current node.

Related to https://github.com/elasticsearch/elasticsearch-analysis-smartcn/pull/13.