Migrate the meat of the repo-content resolver/aggregator logic from DownloadManifestBuilder/RepositoryArchiveBuilder down to cartographer, consolidate those repo-oriented REST endpoints into RepositoryResource, and implement Aprox-aware LocationExpander (from Galley 0.2-SNAPSHOT)
Fixes #43. Remove support for deprecated REST URLs, use client-side redirects instead of RequestDispatcher.forward(), and add a DebugFilter that logs each request to the core (moved from depgraph add-on and generalized).
Fix #41. Impelment optional flag telling the repo/* commands to use local-to-aprox URLs. The default value of the localUrls flag is false (use the remote URL).
Fixes #40. Always return the resolved top-level GAV even if it's already been resolved...unless there's some error condition, of course.
Implementing excluded sources for repo/* configurations, and cleaned up discovery impl a little more.