Support add directory content

A common use case is to add multiple Assets from your directory structure:

addManifestResource("src/main/resources/META-INF/name", "name")
addManifestResource("src/main/resources/META-INF/name2", "name2")

This can be quite painful if you have a lot of items, e.g. html/jsp/jsf

We should support adding of recursive directory content, where target path is resolved as relative to where you add from:

addManifestResource("src/main/resources/META-INF/")

The expected target in the archive would be, root + CONTAINER_PATH + ('file.getName()' + parentDirectory if in a subdirectory of specified import source )

src/main/resources/META-INF/test.html -> (CONTAINER_PATH) + test.html
src/main/resources/META-INF/images/test.jpg -> (CONTAINER_PATH) + images/test.jpg