ResourceMerger is able to merge java archives (jars) and in the process merge
any text based resource files.
The primary use case for this class is when building the smooks-all.jar which
consists of all the jars in the Smooks project. In Smooks there are a few
types of resource files like 'content-handlers.inf', 'data-decoders.inf' that
exist in mulitple jars. This works well when loading resources from the
classpath as all jars will be searched and read. But when there is only a
single jar then only one of the jars resource files will be in the merged jar
and the others will be ignored.