just a bit more type information
did some more experiments only to hit additional problems
improved the signature
filed
this is just a warning and not fatal
added the opt method that returns null
doc improvement
indentation fix
Added PlexusModuleContributor extension point.

This came up with a conversation with JFrog folks who neede to insert a
custom Plexus component to tweak the behaviour.

This scheme allows the caller to insert additional jar files into the
Maven process.