Pluggable implementations of inter-project Ant dependencies.

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