Provides support for source lookup.

## Package Specification

This package provides classes and interfaces to support source lookup. A source lookup director is a persistable source locator that directs source lookup among a collection of source lookup participants and a collection of source containers. Each source lookup participant is a source locator itself, which allows more than one source locator to participate in source lookup for a launch. Each source lookup participant searches for source in the source containers managed by its director, and each participant is notified of changes in the set of source containers being searched.

A source lookup participant participates in source lookup by searching an ordered list of source containers for source elements corresponding to a debug artifact. For example, a participant may be asked to find source corresponding to a stack frame or breakpoint. An implementation of a source lookup participant is debug model specific, since it must convert the debug model artifact (stack frame, breakpoint, etc.), into a source name that can be recognized by a source container, to search for source elements. Source containers are generally debug model independent, whereas source lookup participants are debug model specific.