We need a simple yet effective strategy to make several invocations of ncc build or ncc run in a row re-use as much work as possible.

• FS cache for the CLI
  • Uses the most appropriate location for each OS (like yarn)
  • Flag to ignore it for both run and build (--no-cache)
  • Subcommands to find it and clean it (ncc cache dir and ncc cache clean)
• In-memory interface for the programmatic API (ncc())