Pluggable implementations of inter-project Ant dependencies.

An {@link org.netbeans.modules.ruby.api.project.rake.RakeArtifact} can be used to represent a build product of a sub-project, typically used as a dependency in a parent project. {@link org.netbeans.modules.ruby.spi.project.rake.RakeArtifactProvider} can be used to enumerate artifacts (i.e. targets creating some files) which are recommended for export to parent projects.