Artifact enhancement - add method getArtifactSubDirectory()

I think that it will be nice to have single place in GenericArtifact class
which hided strategy how the directory where artifact file is kept
is named.

Currently the strategy to name this directory is:

getDependency().getType() + "s"

My proposition is to have:

/**

• Get the directory to place the artifact in
  *
• @return The artifact sub directory.
  */
  public String getArtifactSubDirectory() { // simple version. Later this can be made more // complicated by providing more adavanced ArtifactFactoryClasse(s) // but the staregy will be hidden grace to this method return getType()+"s"; }

This will result in possiblity of rewriting methods like getUrlPath in following way:

/** @see Artifact#getUrlPath */
public String getUrlPath()